MarketAxess (MKTX) 10-K 24 Feb 25 2024 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2024	Feb. 20, 2025
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Trading Symbol	MKTX
Entity Registrant Name	MARKETAXESS HOLDINGS INC.
Entity Central Index Key	0001278021
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		37,693,220
Entity Public Float	$ 6.5
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.003 par value
Security Exchange Name	NASDAQ
Entity File Number	001-34091
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	52-2230784
Entity Address, Address Line One	55 Hudson Yards
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10001
Document Annual Report	true
Document Transition Report	false
City Area Code	212
Local Phone Number	813-6000
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for the 2025 Annual Meeting of Stockholders are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K.
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	New York, New York
Auditor Firm ID	238
Auditor Opinion [Text Block]	Opinions on the Financial Statements and Internal Control over Financial Reporting We have audited the accompanying consolidated statements of financial condition of MarketAxess Holdings Inc. and its subsidiaries (the “Company”) as of December 31, 2024 and 2023, and the related consolidated statements of operations, of comprehensive income, of changes in stockholders’ equity and of cash flows for each of the three years in the period ended December 31, 2024, including the related notes (collectively referred to as the “consolidated financial statements”). We also have audited the Company’s internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
ASSETS
Cash and cash equivalents	$ 544,478	$ 451,280
Cash segregated under federal regulations	47,107	45,122
Investments, at fair value	165,260	134,861
Accounts receivable, net of allowance of $982 and $577 as of December 31, 2024 and 2023, respectively	91,845	89,839
Receivables from broker-dealers, clearing organizations and customers	357,728	687,936
Goodwill	236,706	236,706
Intangible assets, net of accumulated amortization	98,078	119,108
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	107,298	102,671
Operating lease right-of-use assets	58,132	63,045
Prepaid expenses and other assets	82,584	84,499
Total assets	1,789,216	2,015,067
Liabilities
Accrued employee compensation	68,054	60,124
Payables to broker-dealers, clearing organizations and customers	218,845	537,398
Income and other tax liabilities	3,683	7,892
Accounts payable, accrued expenses and other liabilities	37,320	37,013
Operating lease liabilities	72,654	79,677
Total liabilities	400,556	722,104
Commitments and Contingencies (Note 13)
Stockholders' equity
Preferred stock	0	0
Common stock	123	123
Additional paid-in capital	350,701	333,292
Treasury stock - Common stock voting, at cost, 3,374,047 shares and 3,041,081 shares as of December 31, 2024 and 2023, respectively	(333,369)	(260,298)
Retained earnings	1,405,904	1,244,216
Accumulated other comprehensive loss	(34,699)	(24,370)
Total stockholders' equity	1,388,660	1,292,963
Total liabilities and stockholders' equity	1,789,216	2,015,067
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock	$ 0	$ 0

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Allowance for accounts receivable	$ 982	$ 577
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	4,855,000	4,855,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.003	$ 0.003
Common stock, shares authorized	110,000,000	110,000,000
Common stock, shares issued	41,020,421	40,940,769
Common stock, shares outstanding	37,646,374	37,899,688
Treasury Stock, Common, Shares	3,374,047	3,041,081
Series A Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	110,000	110,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock Non-Voting [Member]
Common stock, par value	$ 0.003	$ 0.003
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	0	0
Common stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues
Revenues	$ 817,097	$ 752,547	$ 718,300
Expenses
Employee compensation and benefits	235,880	206,926	182,104
Depreciation and amortization	73,824	70,557	61,446
Technology and communications	72,166	62,801	52,964
Professional and consulting fees	27,382	31,935	33,949
Occupancy	14,690	14,216	14,121
Marketing and advertising	11,713	11,049	9,977
Clearing costs	17,863	17,002	17,663
General and administrative	22,709	23,042	19,200
Total expenses	476,227	437,528	391,424
Operating income	340,870	315,019	326,876
Other income (expense)
Interest income	26,046	22,425	5,040
Interest expense	(1,601)	(1,983)	(700)
Equity in earnings of unconsolidated affiliate	1,395	735	1,126
Other, net	(6,164)	(3,496)	5,946
Total other income (expense)	19,676	17,681	11,412
Income before income taxes and equity in undistributed earnings of subsidiaries	360,546	332,700	338,288
Provision for income taxes	86,365	74,645	88,064
Net income	$ 274,181	$ 258,055	$ 250,224
Net income per common share
Basic	$ 7.29	$ 6.87	$ 6.68
Diluted	7.28	6.85	6.65
Cash dividends declared per common share	$ 2.96	$ 2.88	$ 2.8
Weighted average shares outstanding
Basic	37,600	37,546	37,468
Diluted	37,672	37,654	37,643
Commissions [Member]
Revenues
Revenues	$ 711,710	$ 662,964	$ 641,183
Information Services [Member]
Revenues
Revenues	50,540	46,383	39,314
Post-trade Services [Member]
Revenues
Revenues	42,487	40,178	36,877
Technology Services [Member]
Revenues
Revenues	$ 12,360	$ 3,022	$ 926

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 274,181	$ 258,055	$ 250,224
Cumulative translation adjustment	(10,094)	13,349	(24,367)
Net unrealized gain/(loss) on securities available-for-sale, net of tax of $92 and $12, respectively	(235)	(22)	0
Comprehensive income	$ 263,852	$ 271,382	$ 225,857

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Securities available-for-sale, tax expense (benefit)	$ 92	$ 12

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock Voting [Member]	Additional Paid-In Capital [Member]	Treasury Stock - Common Stock Voting	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2021	$ 1,041,309	$ 123	$ 330,262	$ (232,712)	$ 956,966	$ (13,330)
Net Income (Loss)	250,224				250,224
Cumulative translation adjustment	(24,367)					(24,367)
Stock-based compensation	29,864		29,864
Exercise of stock options	672		672
Withholding tax payments on Full Value Awards vesting and stock option exercises	(23,404)		(23,404)
Repurchases of common stock	(87,540)			(87,540)
Treasury stock reclassification			8,074	(8,074)
Cash dividend on common stock	(105,665)				(105,665)
Ending Balance at Dec. 31, 2022	1,081,093	123	345,468	(328,326)	1,101,525	(37,697)
Net Income (Loss)	258,055				258,055
Cumulative translation adjustment	13,349					13,349
Unrealized net gain (loss) on securities available-for-sale, net of tax	(22)					(22)
Stock-based compensation	29,190		29,190
Exercise of stock options	940		940
Withholding tax payments on Full Value Awards vesting and stock option exercises	(25,839)		(25,839)
Reissuance of treasury stock	993		(242)	1,235
Treasury stock used for acquisition	43,841		(16,225)	66,793	(6,727)
Cash dividend on common stock	(108,637)				(108,637)
Ending Balance at Dec. 31, 2023	1,292,963	123	333,292	(260,298)	1,244,216	(24,370)
Net Income (Loss)	274,181				274,181
Cumulative translation adjustment	(10,094)					(10,094)
Unrealized net gain (loss) on securities available-for-sale, net of tax	(235)					(235)
Stock-based compensation	30,847		30,847
Exercise of stock options	2,988		2,988
Withholding tax payments on Full Value Awards vesting and stock option exercises	(16,194)		(16,194)
Reissuance of treasury stock	1,590		(232)	2,403	(581)
Repurchases of common stock	(75,474)			(75,474)
Cash dividend on common stock	(111,912)				(111,912)
Ending Balance at Dec. 31, 2024	$ 1,388,660	$ 123	$ 350,701	$ (333,369)	$ 1,405,904	$ (34,699)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended			12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per common share	$ 0.74	$ 0.72	$ 0.7	$ 2.96	$ 2.88	$ 2.8

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net Income (Loss)	$ 274,181	$ 258,055	$ 250,224
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	73,824	70,557	61,446
Amortization of operating lease right-of-use assets	6,639	5,853	5,708
Stock-based compensation expense	29,684	29,190	29,864
Deferred taxes	(3,878)	(5,815)	(6,547)
Foreign currency transaction losses/(gains)	1,276	4,718	(8,783)
Other	7,042	(3,113)	555
Changes in operating assets and liabilities:
(Increase) in accounts receivable	(3,730)	(7,116)	(15,136)
Decrease/(increase) in receivables from broker-dealers, clearing organizations and customers	320,091	(181,044)	(47,631)
Decrease/(increase) in prepaid expenses and other assets	1,009	(11,898)	(4,249)
Increase in accrued employee compensation	7,049	1,466	(3,417)
(Decrease)/increase in payables to broker-dealers, clearing organizations and customers	(318,229)	227,920	74,668
(Decrease) in income and other tax liabilities	(3,284)	(14,691)	(4,768)
Increase/(decrease) in accounts payable, accrued expenses and other liabilities	3,543	(7,229)	11,384
(Decrease) in operating lease liabilities	(8,730)	(6,735)	(6,373)
Net cash provided by operating activities	385,237	333,767	289,231
Cash flows from investing activities
Proceeds from maturities and sales	12,440	4,452	0
Purchases	(42,810)	(28,818)	0
Acquisitions, net of cash and cash equivalents acquired	0	(78,476)	0
Acquisition of equity method investment	0	0	(34,400)
Purchases of furniture, equipment and leasehold improvements	(9,942)	(9,326)	(13,142)
Capitalization of software development costs	(46,623)	(43,122)	(38,730)
Net cash (used in) investing activities	(86,935)	(155,290)	(86,272)
Cash flows from financing activities
Cash dividends on common stock	(112,697)	(109,658)	(105,942)
Exercise of stock options	2,988	940	672
Withholding tax payments on Full Value Awards vesting and stock option exercises	(16,194)	(25,839)	(23,404)
Repurchases of common stock	(75,474)	0	(87,540)
Payment of contingent consideration	0	(12,500)	(26,164)
Proceeds from short-term borrowings	344,925	123,995	100,000
Repayments of short-term borrowings	(344,925)	(123,995)	(100,000)
Net cash (used in) financing activities	(201,377)	(147,057)	(242,378)
Effect of exchange rate changes on cash and cash equivalents	(8,138)	7,588	(13,484)
Cash and cash equivalents including restricted cash
Net increase for the period	88,787	39,008	(52,903)
Beginning of period	611,672	572,664	625,567
End of period	700,459	611,672	572,664
Supplemental cash flow information
Cash paid for income taxes	96,932	94,814	88,677
Cash paid for interest	1,717	1,870	652
Non-cash investing and financing activity
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	1,840	1,183	1,880
Furniture, equipment, software and leasehold improvement additions included in accounts payable	693	0	0
Stock-based and accrued incentive compensation relating to capitalized software development costs	5,542	0	0
Exercise of stock options - cashless	1,735	0	3,845
Fair value of assets acquired	0	127,635	0
Cash paid for acquisition, net of cash and cash equivalents acquired	0	(78,476)	0
Treasury shares used for acquisition	0	(43,841)	0
Liabilities assumed	0	5,318	0
Trading Investments [Member]
Changes in operating assets and liabilities:
Decrease/(increase) in trading investments	(629)	(25,248)	(49,527)
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
Decrease/(increase) in trading investments	$ (621)	$ (1,103)	$ 1,813

Cybersecurity Risk Management,

Cybersecurity Risk Management, Strategy and Governance	12 Months Ended
	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	I tem 1C. Cybersecurity As a global technology company, and the provider of electronic trading platforms and solutions for fixed-income and other securities, we view cybersecurity as fundamental to our business. Accordingly, we aim to appropriately secure all of our business operations, including information that we generate in the performance of our services, and data provided to us by third parties, including clients, vendors, business partners and employees. Risk Management and Strategy The Company has adopted an Enterprise Risk and Resilience Framework (the “ERRF”) to identify, assess, monitor, and manage the Company’s risks, including cybersecurity risks. Our Chief Risk Officer (the “CRO”) is responsible for implementing and executing the ERRF. The Company’s information security and cybersecurity team is staffed with skilled professionals who manage the safeguarding of our information and is led by our Chief Information Security Officer (the “CISO”). This team is responsible for aligning our practices with the requirements of local regulations and the voluntary standards to which we strive to adhere, such as ISO/IEC 27001 and the National Institute of Standards and Technology (“NIST”) Cybersecurity Framework. The CISO reports directly to our Chief Information Officer (the “CIO”) and CRO. The CIO is responsible for designing and executing the Company’s technology strategy, which includes overseeing the Company’s cybersecurity strategy. The Company’s cybersecurity policies, standards, processes and practices are fully integrated into the Company’s ERRF and are based on recognized frameworks established by NIST, the International Organization for Standardization (“ISO”) and other applicable industry standards. In general, the Company seeks to address cybersecurity risks through a comprehensive, cross-functional approach that is focused on preserving the confidentiality, integrity and availability of the information that the Company collects and stores by identifying, preventing and mitigating cybersecurity threats and effectively responding to cybersecurity incidents when they occur. As one of the critical elements of the Company’s overall ERRF approach, the Company’s cybersecurity program is focused on the following key areas: • Governance: As discussed below in more detail under the heading “The Board’s Oversight of Cybersecurity Risk,” the Board’s oversight of cybersecurity risk management is supported by the Risk Committee of the Board (the “Risk Committee”), which regularly interacts with the Company’s CRO, CIO, CISO and other members of management. • Collaborative Approach: The Company has implemented a comprehensive, cross-functional approach to identification, protection, detection, response and recovery from cybersecurity threats and incidents, while also implementing controls and procedures that are designed to provide for the prompt escalation of certain cybersecurity incidents so that decisions regarding the public disclosure and reporting of such incidents can be made by management in a timely manner. • Technical Safeguards: The Company deploys layered technical safeguards that are designed to protect the Company’s information systems from cybersecurity threats, including firewalls, intrusion prevention and detection systems, anti-malware functionality and access controls, which are evaluated and improved through vulnerability assessments and cybersecurity threat intelligence. • Incident Response and Recovery Planning: The Company has established and maintains its Information Security Incident Management Policy that addresses the Company’s response to a cybersecurity incident, and such policy is tested and evaluated on a regular basis. The policy applies to all full- and part-time employees and contractors. The goal of the policy is to restore normal service operation as quickly as possible following an event, provide timely and accurate information to relevant stakeholders regarding such an event, as appropriate, and minimize the impact of such an event on our business operations. The policy is designed to ensure that we are meeting both our contractual and regulatory requirements related to cybersecurity events. • Data Collection, Use, Processing and Monitoring: The Company maintains policies and procedures relating to our data collection, use and processing activities, as well as mechanisms for monitoring our data systems and usage. We do not have individual retail clients and any gathering and maintaining of individual consumer data is very limited. We seek to maintain compliance with global data protection laws in the countries in which we operate, including the GDPR, the U.K. Data Protection regime and the California Consumer Privacy Act (the “CCPA”). • Third-Party Risk Management: The Company maintains a comprehensive, risk-based approach to identifying and overseeing cybersecurity risks presented by third parties, including vendors, service providers and other external users of the Company’s systems, as well as the systems of third parties that could adversely impact our business in the event of a cybersecurity incident affecting those third-party systems. • Education and Awareness: The Company provides regular, mandatory training for personnel regarding cybersecurity threats in order to equip the Company’s personnel with effective tools to address cybersecurity threats, and to communicate the Company’s evolving information security policies, standards, processes and practices. In addition, the Company provides regular, mandatory training for personnel regarding key data privacy laws and the appropriate collection, use and storage of data. We periodically assess and test our policies, standards, processes and practices that are designed to address cybersecurity threats and incidents. These efforts include a wide range of activities, including audits, assessments, tabletop exercises, vulnerability testing and other exercises focused on evaluating the effectiveness of our cybersecurity measures and planning. The Company regularly engages third parties to perform assessments on our cybersecurity measures, including information security maturity assessments, audits and independent reviews of our information security control environment and operating effectiveness. The results of such assessments, audits and reviews are reported, as appropriate, to the Risk Committee, and the Company adjusts its cybersecurity policies, standards, processes and practices as necessary based on the information provided by these assessments, audits and reviews. We experience cybersecurity threats and incidents from time to time. However, as of the date of this report, we have not experienced a cybersecurity threat or incident that has materially affected the Company, including our business strategy, results of operations, or financial condition, in at least the last three years. While we are not currently aware of any risks from cybersecurity threats that are reasonably likely to materially affect the Company, please see Part I, Item 1A. – “Risk Factors – Malicious cyber-attacks, attempted cybersecurity breaches, and other adverse events affecting our operational systems or infrastructure, or those of third parties, could disrupt our businesses, result in the disclosure of confidential information, damage our reputation and cause losses or regulatory penalties.” The Board’s Oversight of Cybersecurity Risk The Board recognizes the critical importance of maintaining the trust and confidence of our clients, business partners and employees. The Board is actively involved in oversight of the Company’s ERRF, and cybersecurity represents an important component of the Company’s overall approach to enterprise risk management. The Board is responsible for overseeing the Company’s risk management processes over the short-, medium- and long-term by staying informed of the Company’s material risks and evaluating whether management has reasonable controls in place to address such material risks. As part of its oversight responsibilities, the Board dedicates meaningful time and attention to oversight of cybersecurity risk. The Board is not responsible, however, for defining or managing the Company’s various risks. See “Management’s Involvement in Cybersecurity Risk Oversight” below. The Board and its committees oversee risk through regular reports from management. The Board’s committees report on the matters discussed at the committee level to the full Board. The Risk Committee has primary responsibility for cybersecurity oversight. In that capacity, the Risk Committee receives quarterly presentations and reports, as well as additional updates as needed, on cybersecurity matters. Such updates address a wide range of topics including recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, external threat intelligence, technological trends and cybersecurity considerations arising with respect to the Company’s peers and third parties. The Board and the Risk Committee also receive prompt and timely information regarding any cybersecurity incident that meets established internal escalation thresholds, as well as ongoing updates regarding any such incident until it has been addressed. Management’s Involvement in Cybersecurity Risk Oversight The CISO, in coordination with the Information Security Steering Committee, which includes our CEO, CIO, CRO and General Counsel & Corporate Secretary (the “GC”), works collaboratively across the Company to implement a program designed to protect the Company’s information systems from cybersecurity threats and to promptly respond to any cybersecurity incidents in accordance with the Company’s incident response and recovery plans. To facilitate the success of the Company’s cybersecurity risk management program, multidisciplinary teams throughout the Company are deployed to address cybersecurity threats and to respond to cybersecurity incidents. Through ongoing communications with these teams, the CISO and the Information Security Steering Committee monitor the prevention, detection, mitigation and remediation of cybersecurity threats and incidents in real time, and report such threats and incidents to the Risk Committee and/or the full Board when appropriate . The CISO holds undergraduate and masters’ degrees in computer science and cybersecurity, respectively, and has served in various senior roles in information technology and information security for over 20 years, including previously serving as the Chief Information Security Officer of a major global asset manager. The CISO has attained the professional certification of Certified Information System Security Professional (CISSP), Certified Information Security Manager (CISM) and Certified in Risk and Information Systems Control (CRISC). The CIO holds undergraduate and masters’ degrees in computer science and has served in various roles in information technology for over 30 years. The Company’s CRO holds an undergraduate degree and has over 30 years of experience managing risks, including risks arising from cybersecurity threats . The Company is ISO/IEC 27001:2013 certified, which is a global standard that specifies the requirements for establishing, implementing, maintaining, and continually improving information security management systems. Additionally, we have received an independent examination regarding our compliance with SOC 2 Type 1 and Type 2 .
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	The Company’s cybersecurity policies, standards, processes and practices are fully integrated into the Company’s ERRF and are based on recognized frameworks established by NIST, the International Organization for Standardization (“ISO”) and other applicable industry standards. In general, the Company seeks to address cybersecurity risks through a comprehensive, cross-functional approach that is focused on preserving the confidentiality, integrity and availability of the information that the Company collects and stores by identifying, preventing and mitigating cybersecurity threats and effectively responding to cybersecurity incidents when they occur.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	The Board’s Oversight of Cybersecurity Risk The Board recognizes the critical importance of maintaining the trust and confidence of our clients, business partners and employees. The Board is actively involved in oversight of the Company’s ERRF, and cybersecurity represents an important component of the Company’s overall approach to enterprise risk management. The Board is responsible for overseeing the Company’s risk management processes over the short-, medium- and long-term by staying informed of the Company’s material risks and evaluating whether management has reasonable controls in place to address such material risks. As part of its oversight responsibilities, the Board dedicates meaningful time and attention to oversight of cybersecurity risk. The Board is not responsible, however, for defining or managing the Company’s various risks. See “Management’s Involvement in Cybersecurity Risk Oversight” below. The Board and its committees oversee risk through regular reports from management. The Board’s committees report on the matters discussed at the committee level to the full Board. The Risk Committee has primary responsibility for cybersecurity oversight. In that capacity, the Risk Committee receives quarterly presentations and reports, as well as additional updates as needed, on cybersecurity matters. Such updates address a wide range of topics including recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, external threat intelligence, technological trends and cybersecurity considerations arising with respect to the Company’s peers and third parties. The Board and the Risk Committee also receive prompt and timely information regarding any cybersecurity incident that meets established internal escalation thresholds, as well as ongoing updates regarding any such incident until it has been addressed. Management’s Involvement in Cybersecurity Risk Oversight The CISO, in coordination with the Information Security Steering Committee, which includes our CEO, CIO, CRO and General Counsel & Corporate Secretary (the “GC”), works collaboratively across the Company to implement a program designed to protect the Company’s information systems from cybersecurity threats and to promptly respond to any cybersecurity incidents in accordance with the Company’s incident response and recovery plans. To facilitate the success of the Company’s cybersecurity risk management program, multidisciplinary teams throughout the Company are deployed to address cybersecurity threats and to respond to cybersecurity incidents. Through ongoing communications with these teams, the CISO and the Information Security Steering Committee monitor the prevention, detection, mitigation and remediation of cybersecurity threats and incidents in real time, and report such threats and incidents to the Risk Committee and/or the full Board when appropriate . The CISO holds undergraduate and masters’ degrees in computer science and cybersecurity, respectively, and has served in various senior roles in information technology and information security for over 20 years, including previously serving as the Chief Information Security Officer of a major global asset manager. The CISO has attained the professional certification of Certified Information System Security Professional (CISSP), Certified Information Security Manager (CISM) and Certified in Risk and Information Systems Control (CRISC). The CIO holds undergraduate and masters’ degrees in computer science and has served in various roles in information technology for over 30 years. The Company’s CRO holds an undergraduate degree and has over 30 years of experience managing risks, including risks arising from cybersecurity threats . The Company is ISO/IEC 27001:2013 certified, which is a global standard that specifies the requirements for establishing, implementing, maintaining, and continually improving information security management systems. Additionally, we have received an independent examination regarding our compliance with SOC 2 Type 1 and Type 2 .
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Risk Committee has primary responsibility for cybersecurity oversight.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Board and its committees oversee risk through regular reports from management. The Board’s committees report on the matters discussed at the committee level to the full Board. The Risk Committee has primary responsibility for cybersecurity oversight. In that capacity, the Risk Committee receives quarterly presentations and reports, as well as additional updates as needed, on cybersecurity matters. Such updates address a wide range of topics including recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, external threat intelligence, technological trends and cybersecurity considerations arising with respect to the Company’s peers and third parties. The Board and the Risk Committee also receive prompt and timely information regarding any cybersecurity incident that meets established internal escalation thresholds, as well as ongoing updates regarding any such incident until it has been addressed.
Cybersecurity Risk Role of Management [Text Block]	Management’s Involvement in Cybersecurity Risk Oversight The CISO, in coordination with the Information Security Steering Committee, which includes our CEO, CIO, CRO and General Counsel & Corporate Secretary (the “GC”), works collaboratively across the Company to implement a program designed to protect the Company’s information systems from cybersecurity threats and to promptly respond to any cybersecurity incidents in accordance with the Company’s incident response and recovery plans. To facilitate the success of the Company’s cybersecurity risk management program, multidisciplinary teams throughout the Company are deployed to address cybersecurity threats and to respond to cybersecurity incidents. Through ongoing communications with these teams, the CISO and the Information Security Steering Committee monitor the prevention, detection, mitigation and remediation of cybersecurity threats and incidents in real time, and report such threats and incidents to the Risk Committee and/or the full Board when appropriate . The CISO holds undergraduate and masters’ degrees in computer science and cybersecurity, respectively, and has served in various senior roles in information technology and information security for over 20 years, including previously serving as the Chief Information Security Officer of a major global asset manager. The CISO has attained the professional certification of Certified Information System Security Professional (CISSP), Certified Information Security Manager (CISM) and Certified in Risk and Information Systems Control (CRISC). The CIO holds undergraduate and masters’ degrees in computer science and has served in various roles in information technology for over 30 years. The Company’s CRO holds an undergraduate degree and has over 30 years of experience managing risks, including risks arising from cybersecurity threats .
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	The CISO, in coordination with the Information Security Steering Committee, which includes our CEO, CIO, CRO and General Counsel & Corporate Secretary (the “GC”), works collaboratively across the Company to implement a program designed to protect the Company’s information systems from cybersecurity threats and to promptly respond to any cybersecurity incidents in accordance with the Company’s incident response and recovery plans.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	The CISO holds undergraduate and masters’ degrees in computer science and cybersecurity, respectively, and has served in various senior roles in information technology and information security for over 20 years, including previously serving as the Chief Information Security Officer of a major global asset manager. The CISO has attained the professional certification of Certified Information System Security Professional (CISSP), Certified Information Security Manager (CISM) and Certified in Risk and Information Systems Control (CRISC). The CIO holds undergraduate and masters’ degrees in computer science and has served in various roles in information technology for over 30 years. The Company’s CRO holds an undergraduate degree and has over 30 years of experience managing risks, including risks arising from cybersecurity threats .
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Through ongoing communications with these teams, the CISO and the Information Security Steering Committee monitor the prevention, detection, mitigation and remediation of cybersecurity threats and incidents in real time, and report such threats and incidents to the Risk Committee and/or the full Board when appropriate .
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 274,181	$ 258,055	$ 250,224

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	(b) Trading Plans In the fourth quarter of 2024 , no director or officer (as defined in Exchange Act Rule 16a-1(f)) of the Company adopted or terminated a Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement for the purchase or sale of securities of the Company, within the meaning of Item 408 of Regulation S-K, except as follows: Scott Pintoff , General Counsel & Corporate Secretary , adopted a trading arrangement intended to satisfy Rule 10b5-1(c) on December 5, 2024 , for the sale of up to 2,225 shares of the Company’s common stock, subject to certain conditions. The arrangement’s expiration date is February 20, 2026 .
Name	Scott Pintoff
Title	General Counsel & Corporate Secretary
Rule 10b5-1 Arrangement Adopted	true
Non-Rule 10b5-1 Arrangement Adopted	false
Adoption Date	December 5, 2024
Rule 10b5-1 Arrangement Terminated	true
Non-Rule 10b5-1 Arrangement Terminated	false
Termination Date	February 20, 2026
Arrangement Duration	442 days
Aggregate Available	2,225

Organization and Principal Busi

Organization and Principal Business Activity	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Organization and Principal Business Activity	1. Organization and Principal Busine ss Activity MarketAxess Holdings Inc. was incorporated in the State of Delaware on April 11, 2000 . Through its subsidiaries, MarketAxess operates leading electronic trading platforms delivering expanded liquidity opportunities, improved execution quality and significant cost savings across global fixed-income markets. Approximately 2,100 institutional investor and broker-dealer firms use MarketAxess’ patented trading technology to access global liquidity on its platforms in U.S. high-grade bonds, U.S. high-yield bonds, emerging market debt, Eurobonds, municipal bonds, U.S. government bonds and other fixed-income securities. MarketAxess offers a diverse set of trading protocols, automated and algorithmic trading solutions, intelligent data products and a range of post-trade and technology services to provide an end-to-end trading solution to its network of platform participants. Through its Open Trading® protocols, MarketAxess executes bond trades between and among institutional investor and broker-dealer clients in the leading all-to-all anonymous trading environment for corporate bonds.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis of Presentation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated. Cash and Cash Equivalents The Company defines cash equivalents as short-term interest-bearing investments with maturities at the time of purchase of three months or less. Investments The Company determines the appropriate classification of securities at the time of purchase which are recorded in the Consolidated Statements of Financial Condition on the trade date. Securities are classified as available-for-sale or trading. Available-for-sale investments are carried at fair value with unrealized gains or losses reported in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition and realized gains or losses reported in other, net in the Consolidated Statements of Operations. Trading investments include U.S. Treasuries and are carried at fair value, with realized and unrealized gains or losses included in other, net in the Consolidated Statements of Operations. The Company assesses whether an impairment loss on its available-for-sale debt securities has occurred due to declines in fair value or other market conditions. When the amortized cost basis of an available-for-sale debt security exceeds its fair value, the security is deemed to be impaired. The portion of an impairment related to credit losses is determined by comparing the present value of cash flows expected to be collected from the security with the amortized cost basis of the security and is recorded as a charge in the Consolidated Statements of Operations. The remainder of an impairment is recognized in accumulated other comprehensive loss if the Company does not intend to sell the security and it is more likely than not that the Company will not be required to sell the security prior to recovery. Fair Value Financial Instruments Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” A three-tiered hierarchy for determining fair value has been established that prioritizes inputs to valuation techniques used in fair value calculations. The three levels of inputs are defined as Level 1 (unadjusted quoted prices for identical assets or liabilities in active markets), Level 2 (inputs that are observable in the marketplace other than those inputs classified in Level 1) and Level 3 (inputs that are unobservable in the marketplace). The Company’s financial assets and liabilities measured at fair value on a recurring basis consist of its money market funds, trading securities, available-for-sale securities and foreign currency forward contracts. All other financial instruments are short-term in nature and the carrying amounts reported on the Consolidated Statements of Financial Condition approximate fair value. Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers Receivables from broker-dealers, clearing organizations and customers include amounts receivable for securities not delivered by the Company to the purchaser by the settlement date (“securities failed-to-deliver”) and cash deposits held at clearing organizations and clearing brokers to facilitate the settlement and clearance of matched principal transactions. Payables to broker-dealers, clearing organizations and customers include amounts payable for securities not received by the Company from a seller by the settlement date (“securities failed-to-receive”). Securities failed-to-deliver and securities failed-to-receive for transactions executed on a matched principal basis where the Company serves as a counterparty to both the buyer and the seller are recorded on a settlement date basis. The Company presents its securities failed-to-deliver and securities failed-to-receive balances on a net-by-counterparty basis within receivables from and payables to broker-dealers, clearing organizations and customers. The difference between the Company’s trade-date receivables and payables for unsettled matched principal transactions reflects commissions earned and is recorded within accounts receivable, net on a trade date basis. Allowance for Credit Losses All accounts receivable have contractual maturities of less than one year and are derived from trading-related fees and commissions and revenues from products and services. The Company continually monitors collections and payments from its customers and maintains an allowance for doubtful accounts. The allowance for credit losses is based on the estimated expected credit losses in accounts receivable, as determined from a review of aging schedules, past due balances, historical collection experience and other specific collection issues that have been identified. Account balances are grouped for evaluation based on various risk characteristics, including billing type, legal entity, and geographic region. Additions to the allowance for credit losses are charged to bad debt expense, which is included in general and administrative expense in the Company’s Consolidated Statements of Operations. Balances that are determined to be uncollectable are written off against the allowance for credit losses. The allowance for credit losses was $ 1.0 million and $ 0.6 million as of December 31, 2024 and 2023 , respectively. The provision for bad debts was $ 0.8 million, $ 0.4 million and $ 0.6 million for the years ended December 31, 2024, 2023 and 2022, respectively. Write-offs and other charges against the allowance for credit losses were $ 0.4 million, $ 0.3 million and $ 0.1 million for the years ended December 31, 2024, 2023 and 2022, respectively. Depreciation and Amortization Fixed assets are carried at cost less accumulated depreciation. The Company uses the straight-line method of depreciation over three to seven years . The Company amortizes leasehold improvements on a straight-line basis over the lesser of the life of the improvement or the remaining term of the lease. Software Development Costs The Company capitalizes certain costs associated with the development of internal use software, including, among other items, employee compensation and related benefits and third-party consulting costs at the point at which the conceptual formulation, design and testing of possible software project alternatives have been completed. Once the product is ready for its intended use, such costs are amortized on a straight-line basis over three to five years . The Company reviews the amounts capitalized for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable. Cloud Computing Costs The Company capitalizes certain costs associated with cloud computing arrangements, including, among other items, vendor software development costs billed to us that are part of the application development stage. These costs are recorded as a prepaid asset on the Consolidated Statements of Financial Condition and are amortized over the period of the hosting service contract, which ranges from one to five years . The Company reviews the amounts capitalized for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable. Foreign Currency Translation and Forward Contracts Assets and liabilities denominated in foreign currencies are translated using exchange rates at the end of the period; revenues and expenses are translated at average monthly rates. Gains and losses on foreign currency translation are a component of accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Transaction gains and losses are recorded in other, net in the Consolidated Statements of Operations. The Company enters into foreign currency forward contracts to economically hedge its foreign currency transaction gains and losses. Realized and unrealized gains and losses on these forward contracts are included in other, net in the Consolidated Statements of Operations. The Company records the fair value of the forward contract asset in prepaid expenses and other assets or the fair value of the forward contract liability in accounts payable, accrued expenses and other liabilities in the Consolidated Statements of Financial Condition. Revenue Recognition The Company’s classification of revenues in the Consolidated Statements of Operations represents revenues from contracts with customers disaggregated by type of revenue. The Company has four revenue streams as described below. Commission Revenue – The Company charges its broker-dealer clients variable transaction fees for trades executed on its platforms and, under certain plans, distribution fees or monthly minimum fees to use the platforms for a particular product area. Variable transaction fees are recognized on a trade date basis, are generally calculated as a percentage of the notional dollar volume of bonds traded on the platforms and vary based on the type, size, yield and maturity of the bond traded, as well as individual client incentives. Bonds that are more actively traded or that have shorter maturities generally generate lower commissions, while bonds that are less actively traded or that have longer maturities generally command higher commissions. Under the Company’s disclosed trading transaction fee plans, variable transaction fees, distribution fees and unused monthly fee commitments are invoiced and recorded on a monthly basis. For Open Trading trades that the Company executes between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller, the Company earns its commission through the difference in price between the two trades. The commission is collected upon settlement of the trade, which typically occurs within one to two trading days after the trade date. For the majority of the Company’s U.S. Treasury matched principal trades, commissions are invoiced and recorded on a monthly basis. Following the Pragma Acquisition in the fourth quarter of 2023, the Company also earns other commissions on equities and foreign exchange products for algorithmic trading services. These fees incorporate variable transaction fees, which are calculated as a percentage of the notional dollar volume traded and are billed on a monthly basis. The following table presents commission revenue by fee type: Year Ended December 31, 2024 2023 2022 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 361,252 $ 323,038 $ 321,603 Open Trading – matched principal trading 177,966 178,517 175,440 U.S. government bonds - matched principal trading 19,310 15,222 16,978 Other 20,016 4,979 — Total variable transaction fees 578,544 521,756 514,021 Distribution fees and unused minimum fees 133,166 141,208 127,162 Total commissions $ 711,710 $ 662,964 $ 641,183 Information services – Information services includes data licensed to the Company’s broker-dealer clients, institutional investor clients and data-only subscribers; professional and consulting services; technology software licenses; and maintenance and support services. The nature and timing of each performance obligation may vary as these contracts are either subscription-based services transferred over time, and may be net of volume-based discounts, or one-time services that are transferred at a point in time. Revenues for services transferred over time are recognized ratably over the contract period as the Company’s performance obligation is met, whereas revenues for services transferred at a point in time are recognized in the period the services are provided. Customers are generally billed monthly, quarterly, or annually; revenues billed in advance are deferred and recognized ratably over the contract period. The following table presents information services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Information services revenue by timing Services transferred over time $ 49,560 $ 45,102 $ 38,452 Services transferred at a point in time 980 1,281 862 Total information services revenues $ 50,540 $ 46,383 $ 39,314 Post-trade services – Post-trade services revenue is generated from regulatory transaction reporting, trade publication and post-trade matching services. Customers are generally billed monthly in arrears and revenue is recognized in the period transactions are processed. Revenues billed in advance are deferred and recognized ratably over the contract period. The Company also generates one-time implementation fees for onboarding clients, which are invoiced and recognized in the period the implementation is completed. The following table presents post-trade services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Post-trade services revenue by timing Services transferred over time $ 42,170 $ 40,061 $ 36,835 Services transferred at a point in time 317 117 42 Total post-trade services revenues $ 42,487 $ 40,178 $ 36,877 Technology services – Technology services revenue primarily includes technology services revenue generated by Pragma and revenue from telecommunications line charges to broker-dealer clients. Customers may be billed monthly or quarterly in arrears or in advance, and revenue is recognized in the period transactions are processed. Revenues billed in advance are deferred and recognized ratably over the contract period. The following table presents technology services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Technology services revenue by timing Services transferred over time $ 12,334 $ 3,021 $ 926 Services transferred at a point in time 26 1 - Total technology services revenues $ 12,360 $ 3,022 $ 926 Contract liabilities consist of deferred revenues that the Company records when cash payments are received or due in advance of services to be performed. Deferred revenues are included in accounts payable, accrued expenses and other liabilities on the Consolidated Statements of Financial Condition. The revenue recognized from contract liabilities and the remaining balance is shown below: December 31, 2023 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2024 (In thousands) Information services $ 3,049 $ 14,948 $ ( 14,695 ) $ — $ 3,302 Post-trade services 923 20,436 ( 20,060 ) ( 13 ) 1,286 Technology services 567 8,213 ( 8,365 ) — 415 Total deferred revenue $ 4,539 $ 43,597 $ ( 43,120 ) $ ( 13 ) $ 5,003 The majority of the Company’s information services and post-trade services contracts are short-term in nature with durations of less than one year. For contracts with original durations extending beyond one year, the aggregate amount of the transaction price allocated to remaining performance obligations was $ 47.0 million as of December 31, 2024 . The Company expects to recognize revenue associated with the remaining performance obligations over the next 46 months. Stock-Based Compensation The Company measures and recognizes compensation expense for all share-based payment awards based on their estimated fair values measured as of the grant date. These costs are recognized as an expense in the Consolidated Statements of Operations over the requisite service period, which is typically the vesting period, with an offsetting increase to additional paid-in capital. Forfeitures are recognized as they occur. Income Taxes Income taxes are accounted for using the asset and liability method. Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recognized against deferred tax assets if it is more likely than not that such assets will not be realized in future years. Tax benefits for uncertain tax positions are recognized when it is more likely than not that the positions will be sustained upon examination based on their technical merits. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes in the Consolidated Statements of Operations. All tax effects related to share-based payments are recorded in the provision for income taxes in the periods during which the awards are exercised or vest. Business Combinations, Goodwill and Intangible Assets Business combinations are accounted for under the purchase method of accounting. The total cost of an acquisition is allocated to the underlying net assets based on their respective estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Determining the fair value of certain assets acquired and liabilities assumed requires judgment and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash flows, discount rates, revenue growth rates, customer attrition rates, royalty rates, obsolescence and asset lives. Intangible assets are valued using various methodologies, including the relief-from-royalty method and multi-period excess earnings method. The Company operates as a single reporting unit. Following an acquisition, goodwill no longer retains its identification with a particular acquisition, but instead becomes identifiable with the entire reporting unit. As a result, all of the fair value of the Company is available to support the value of goodwill. An impairment review of goodwill is performed on an annual basis, at year-end, or more frequently if circumstances change. Intangible assets with definite lives, including purchased technologies, customer relationships and other intangible assets, are amortized over their estimated useful lives which range from one to 15 years using either a straight-line or accelerated amortization method based on the pattern of economic benefit the Company expects to realize from such assets. Intangible assets are assessed for impairment when events or circumstances indicate the existence of a possible impairment. Equity Investments and Consolidation The Company evaluates equity investments for potential consolidation under the voting-interest or variable-interest models. The Company consolidates investees over which the Company determines it has control under the voting interest model, generally greater than 50% ownership, or for which the Company is the primary beneficiary under the variable-interest model. The Company uses the equity method of accounting when it exercises significant influence over the investee, but does not have operating control, generally between 20% and 50% ownership. Under the equity method of accounting, original investments are recorded at cost in prepaid expenses and other assets on the Consolidated Statements of Financial Condition and adjusted by the Company’s proportionate share of the investees’ undistributed earnings or losses. Equity investments are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the investment may not be recoverable. Earnings Per Share Basic earnings per share is computed by dividing the net income attributable to common stock by the weighted-average number of shares of common stock outstanding during the period. For purposes of computing diluted earnings per share, the weighted-average shares outstanding of common stock reflects the dilutive effect that could occur if convertible securities or other contracts to issue common stock were converted into or exercised for common stock. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recent Accounting Pronouncements In November 2023, Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The ASU expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly reviewed by the chief operating decision maker (“CODM”) and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items and interim disclosures of a reportable segment’s profit or loss and assets. The ASU also requires the disclosure of the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. All disclosure requirements under ASU 2023-07 and existing segment disclosures in ASC 280, Segment Reporting are also required for public entities with a single reportable segment. The ASU is effective for the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and subsequent interim periods. The ASU must be applied retrospectively to all periods presented in the financial statements. The Company adopted this standard for the year ended December 31, 2024. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation and income taxes paid. The ASU is effective for the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025. The guidance may be applied on a prospective or retrospective basis and early adoption is permitted. Adoption of this ASU will result in additional disclosures, but will not have an impact on the Company’s consolidated statements of financial condition, operations and cash flows. In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses . The ASU primarily will require enhanced disclosures about certain types of expenses. The amendments in ASU 2024-03 are effective for fiscal years beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027, and may be applied either on a prospective or retrospective basis. The Company is currently evaluating the impact of the standard on its disclosures.

Regulatory Capital Requirements

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2024
Broker-Dealer [Abstract]
Regulatory Capital Requirements	3. Regulatory Capital Requirements Certain of the Company’s U.S. subsidiaries are registered as broker-dealers and are subject to the applicable rules and regulations of the SEC, FINRA and the CFTC. These rules contain minimum net capital requirements, as defined in the applicable regulations. Certain of the Company’s foreign subsidiaries are regulated by the FCA in the U.K. or other foreign regulators and must maintain financial resources, as defined in the applicable regulations, in excess of the applicable financial resources requirement. As of December 31, 2024, each of the Company’s subsidiaries that are subject to these regulations had net capital or financial resources in excess of their minimum requirements. As of December 31, 2024, the Company’s subsidiaries maintained aggregate net capital and financial resources that were $ 574.6 million in excess of the required levels of $ 33.8 million. One of the Company’s U.S. broker-dealer subsidiaries is required to segregate funds in a special reserve bank account for the benefit of customers pursuant to Rule 15c3-3 of the Exchange Act. As of December 31, 2024, the U.S. broker-dealer subsidiary had a balance of $ 47.1 million in its special reserve bank account. This U.S. broker-dealer subsidiary also maintained net capital that was $ 318.9 million in excess of the required level of $ 2.3 million. Each of the Company’s U.S. and foreign regulated subsidiaries are subject to local regulations which generally limit, or require the prior notification to or approval from such regulated entity’s principal regulator before, the repayment of borrowings from the Company or affiliates, paying cash dividends, making loans to the Company or affiliates or otherwise entering into transactions that result in a significant reduction in regulatory net capital or financial resources.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The following table summarizes the valuation of the Company’s assets and liabilities measured at fair value as categorized based on the hierarchy described in Note 2: Level 1 Level 2 Level 3 Total (In thousands) As of December 31, 2024 Assets Money market funds $ 55,473 $ — $ — $ 55,473 Securities available-for-sale Corporate debt — 55,108 — 55,108 Trading securities U.S. Treasuries — 99,045 — 99,045 Mutual funds held in rabbi trust — 11,107 — 11,107 Total assets $ 55,473 $ 165,260 $ — $ 220,733 Liabilities Foreign currency forward position — 936 — 936 Total liabilities $ — $ 936 $ — $ 936 As of December 31, 2023 Assets Money market funds $ 18,634 $ — $ — $ 18,634 Securities available-for-sale Corporate debt — 24,694 — 24,694 Trading securities U.S. Treasuries — 99,682 — 99,682 Mutual funds held in rabbi trust — 10,485 — 10,485 Foreign currency forward position — 1,901 — 1,901 Total assets $ 18,634 $ 136,762 $ — $ 155,396 Money market funds are included in cash and cash equivalents on the Consolidated Statements of Financial Condition. Securities available-for-sale and trading securities are included in investments, at fair value on the Consolidated Statements of Financial Condition. Securities classified within Level 2 were valued using a market approach utilizing prices and other relevant information generated by market transactions involving comparable assets. The foreign currency forward contracts are included in either other assets or accounts payable, accrued expenses and other liabilities on the Consolidated Statements of Financial Condition, and are classified within Level 2 as the valuation inputs are based on quoted market prices. The mutual funds held in a rabbi trust represent investments associated with the Company’s deferred cash incentive plan. The table below presents the carrying value, fair value and fair value hierarchy category of the Company’s financial assets and liabilities that are not measured at fair value on the Consolidated Statements of Financial Condition. The carrying values of the Company’s financial assets and liabilities not measured at fair value categorized in the fair value hierarchy as Level 1 and Level 2 approximate fair value due to the short-term nature of the underlying assets and liabilities. Carrying Value Fair Value Level 1 Level 2 Level 3 Total (In thousands) As of December 31, 2024 Financial assets not measured at fair value: Cash $ 489,005 $ 489,005 $ 489,005 $ — $ — $ 489,005 Cash segregated under federal regulations 47,107 47,107 47,107 — — 47,107 Accounts receivable, net of allowance 91,845 91,845 — 91,845 — 91,845 Receivables from broker-dealers, clearing 357,728 357,728 107,652 250,076 — 357,728 Total $ 985,685 $ 985,685 $ 643,764 $ 341,921 $ — $ 985,685 Financial liabilities not measured at fair value: Payables to broker-dealers, clearing $ 218,845 $ 218,845 $ — $ 218,845 $ — $ 218,845 As of December 31, 2023 Financial assets not measured at fair value: Cash $ 432,646 $ 432,646 $ 432,646 $ — $ — $ 432,646 Cash segregated under federal regulations 45,122 45,122 45,122 — — 45,122 Accounts receivable, net of allowance 89,839 89,839 — 89,839 — 89,839 Receivables from broker-dealers, clearing 687,936 687,936 115,151 572,785 — 687,936 Total $ 1,255,543 $ 1,255,543 $ 592,919 $ 662,624 $ — $ 1,255,543 Financial liabilities not measured at fair value: Payables to broker-dealers, clearing $ 537,398 $ 537,398 $ — $ 537,398 $ — $ 537,398 During the years ended December 31, 2024 and 2023 , there were no transfers of securities between Level 1, Level 2 and Level 3. The Company enters into foreign currency forward contracts as an economic hedge against certain foreign currency transaction gains and losses in the Consolidated Statements of Operations. These forward contracts are for three-month periods and are used to limit exposure to foreign currency exchange rate fluctuations. The Company records the fair value of the asset in prepaid expenses and other assets or the fair value of the liability in accounts payable, accrued expenses and other liabilities in the Consolidated Statements of Financial Condition. The following table summarizes the Company’s foreign currency forward position: As of December 31, 2024 December 31, 2023 (In thousands) Notional value $ 64,454 $ 61,858 Fair value of notional 63,518 63,759 Fair value of the (liability)/asset $ ( 936 ) $ 1,901 Realized and unrealized gains and losses on foreign currency forward contracts are included in other, net in the Consolidated Statements of Operations. The following table summarizes the realized and unrealized gains and losses on foreign currency forward contracts: Year Ended December 31, 2024 2023 2022 (In thousands) Unrealized gain/(loss) $ ( 2,838 ) $ 3,590 ( 1,688 ) Realized gain/(loss) 1,148 ( 1,470 ) $ 802 Total gain/(loss) $ ( 1,690 ) $ 2,120 $ ( 886 ) The Company records cash collateral deposits with its counterparty bank in prepaid expenses and other assets on the Consolidated Statements of Financial Condition. As of December 31, 2024, the Company maintained a cash collateral deposit of $ 1.1 million with its counterparty bank. The following table summarizes the Company’s investments: Amortized Gross Gross Fair (In thousands) As of December 31, 2024 Securities available-for-sale Corporate debt $ 55,447 $ 88 $ ( 427 ) $ 55,108 Trading securities U.S. Treasuries 100,484 86 ( 1,525 ) 99,045 Mutual funds held in rabbi trust 10,212 900 ( 5 ) 11,107 Total investments $ 166,143 $ 1,074 $ ( 1,957 ) $ 165,260 As of December 31, 2023 Securities available-for-sale Corporate debt $ 24,705 $ 55 $ ( 66 ) $ 24,694 Trading securities U.S. Treasuries 99,236 446 — 99,682 Mutual funds held in rabbi trust 10,962 172 ( 649 ) 10,485 Total investments $ 134,903 $ 673 $ ( 715 ) $ 134,861 Proceeds from the sales and maturities of investments were $ 62.4 million and $ 29.5 million for the years ended December 31, 2024 and 2023, respectively. Purchases of investments were $ 93.4 million and $ 78.6 million for the years ended December 31, 2024 and 2023, respectively. The following table summarizes the Company’s unrealized and realized gains and losses on investments: Year Ended December 31, 2024 2023 2022 (In thousands) Unrealized gains/(losses) Securities available-for-sale Corporate debt $ ( 328 ) $ ( 11 ) $ — Trading securities U.S. Treasuries ( 1,025 ) 446 ( 534 ) Mutual funds held in rabbi trust 1,372 1,284 ( 2,091 ) Total investments $ 19 $ 1,719 $ ( 2,625 ) Realized gains/(losses) Securities available-for-sale Corporate debt $ 4 $ ( 11 ) $ — Trading securities Mutual funds held in rabbi trust ( 328 ) ( 138 ) — Total investments $ ( 324 ) $ ( 149 ) $ — Liabilities: Securities sold, not yet purchased $ 174 $ — $ — Unrealized gains and losses on securities available-for-sale are included in accumulated other comprehensive loss on the Consolidated Statements of Financial Condition. Realized gains and losses on securities available-for-sale and realized and unrealized gains and losses on trading securities are included in other, net on the Consolidated Statements of Operations. The following table summarizes the fair value of the Company’s corporate debt and U.S. Treasury investments based upon the contractual maturities: Less than one year Due in 1 - 5 years Total (In thousands) As of December 31, 2024 Securities available-for-sale Corporate debt $ 9,346 $ 45,762 $ 55,108 Trading securities U.S. Treasuries 49,978 49,067 99,045 Total $ 59,324 $ 94,829 $ 154,153 As of December 31, 2023 Securities available-for-sale Corporate debt $ 10,727 $ 13,967 $ 24,694 Trading securities U.S. Treasuries 49,756 49,926 99,682 Total $ 60,483 $ 63,893 $ 124,376 The following table provides fair values and unrealized losses on the Company’s available-for-sale investments and the aging of securities’ continuous unrealized loss position: Less than Twelve Months Twelve Months or More Total Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses (In thousands) As of December 31, 2024 Corporate debt $ 38,041 $ ( 426 ) $ 1,226 $ ( 1 ) $ 39,267 $ ( 427 ) As of December 31, 2023 Corporate debt $ 17,658 $ ( 66 ) $ — $ — $ 17,658 $ ( 66 ) During the years ended December 31, 2024, 2023 and 2022 , the Company did no t recognize any credit losses on its available-for-sale securities. The unrealized losses on securities are due to changes in interest rates and market liquidity.

Receivables from and Payables t

Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers	12 Months Ended
	Dec. 31, 2024
Due to and from Broker-Dealers and Clearing Organizations [Abstract]
Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers	5. Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers Receivables from and payables to broker-dealers, clearing organizations and customers consisted of the following: As of December 31, 2024 December 31, 2023 Receivables from broker-dealers, clearing organizations and customers: (In thousands) Securities failed-to-deliver – broker-dealers and clearing organizations $ 109,307 $ 282,125 Securities failed-to-deliver – customers 136,424 284,322 Cash deposits with clearing organizations and broker-dealers 107,652 115,151 Other 4,345 6,338 Total $ 357,728 $ 687,936 Payables to broker-dealers, clearing organizations and customers: Securities failed-to-receive – broker-dealers and clearing organizations $ 158,694 $ 125,022 Securities failed-to-receive – customers 51,916 405,186 Other 8,235 7,190 Total $ 218,845 $ 537,398

Acquisitions and Equity Investm

Acquisitions and Equity Investments	12 Months Ended
	Dec. 31, 2024
Business Combinations [Abstract]
Acquisitions and Equity Investments	6. Acquisitions and Equity Investments Acquisition of Pragma On October 2, 2023, the Company completed its acquisition (the “Pragma Acquisition”) of all of the outstanding ownership interests of Pragma LLC and Pragma Financial Systems LLC (collectively “Pragma”) pursuant to the terms and conditions of a Membership Interest Purchase Agreement entered into among the Company, Pragma Weeden Holdings LLC, Pragma Financial Systems LLC, Pragma LLC and, solely for certain limited purposes, David Mechner, Pragma’s chief executive officer, on August 5, 2023 (the “Purchase Agreement”). Following customary adjustments for cash, debt, transaction expenses and working capital, the aggregate purchase price for the Pragma Acquisition was $ 125.0 million, comprised of approximately $ 81.2 million in cash and 224,776 shares of common stock of the Company, valued at approximately $ 43.8 million as of the closing date of the Pragma Acquisition, as described below. A portion of the stock consideration, amounting to 8,603 shares of common stock, was placed in escrow for 12 months to secure the sellers’ indemnification obligations under the Purchase Agreement. In addition, pursuant to the Purchase Agreement and subject to certain exceptions, the sellers and their affiliates were prohibited from transferring any of the Company common stock received in the Pragma Acquisition for a period of six months following the October 2, 2023 closing date. The value ascribed to the shares by the Company was discounted from the market value on the date of closing to reflect the non-marketability of such shares during the restriction period. Pragma is a quantitative trading technology provider specializing in algorithmic and analytical services. Pragma LLC is a registered broker-dealer. The Company has performed an allocation of the purchase price to the fair value of assets acquired and liabilities assumed at the date of acquisition. The Company utilized an independent third-party to assist in determining the fair value of the acquired intangible assets. The purchase price allocation is as follows (in thousands): Purchase price $ 125,002 Less: acquired cash ( 2,685 ) Purchase price, net of acquired cash 122,317 Intangible assets ( 38,900 ) Accounts receivable ( 2,637 ) Prepaid expenses and other assets ( 4,181 ) Accounts payable, accrued expenses and other liabilities 5,318 Goodwill $ 81,917 The acquired developed technology and customer relationships intangible assets were valued using the relief-from-royalty method and multi-period excess earnings method, respectively. The fair values of the intangible assets acquired are as follows (in thousands, except for useful lives): Costs Useful Lives Developed technology $ 28,500 7 years Customer relationships 9,200 15 years Tradename - finite life 1,200 15 years Total $ 38,900 The goodwill recognized in connection with the Pragma Acquisition is primarily attributable to the acquisition of an assembled workforce and expected future technology and synergies from the integration of the operations of Pragma into the Company’s operations. All of the goodwill recognized in connection with the Pragma Acquisition is expected to be deductible for income tax purposes. Pro forma financial information and current period results for the Pragma Acquisition were not material to the Company’s consolidated financial statements and therefore have not been presented. RFQ Hub LLC Equity Investment In May 2022, the Company invested $ 34.4 million to acquire a minority ownership stake in RFQ–hub Holdings LLC, an entity formed with a consortium of market participants to support the growth of RFQ-hub, a multi-asset request for quote platform. The Company possesses significant influence over RFQ–hub Holdings LLC and is accounting for its investment under the equity method of accounting . As of December 31, 2024, the Company’s investment is recorded at carrying value of $ 34.4 million within prepaid expenses and other assets on the Consolidated Statements of Financial Condition. The Company’s proportionate share of RFQ–hub Holdings LLC’s net earnings was $ 1.4 million and $ 0.7 million for the years ended December 31, 2024 and 2023 , respectively, and is recorded within equity in earnings of unconsolidated affiliate on the Consolidated Statements of Operations. In October 2024, the Company received a distribution from RFQ-hub Holdings LLC of $ 3.2 million. Under a services agreement, the Company charges its equity method investee for certain reimbursable support costs incurred by the Company, including personnel compensation, and certain operational overhead costs. The amounts billed for the years ended December 31, 2024 and 2023 were $ 2.1 million and $ 1.1 million, respectively, and are included within other, net on the Consolidated Statements of Operations. The receivable from the equity method investee was $ 0.6 million as of December 31, 2024 and is included within accounts receivable, net on the Consolidated Statements of Financial Condition. On April 19, 2024, the Company entered into an agreement to acquire an additional 49.0 % interest in RFQ–hub Holdings LLC for approximately $ 37.9 million of cash consideration. The acquisition is subject to various closing conditions, including the receipt of certain regulatory approvals. Upon the closing of the acquisition, the Company will hold a 92.0 % controlling stake in RFQ-hub Holdings LLC .

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	7. Goodwill and Intangible Assets Goodwill and intangible assets with indefinite lives were $ 236.7 million as of each December 31, 2024 and 2023, respectively. Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2024 December 31, 2023 Cost Accumulated Net carrying Cost Accumulated Net carrying (In thousands) Customer relationships $ 138,089 $ ( 64,698 ) $ 73,391 $ 140,348 $ ( 50,987 ) $ 89,361 Technology and other intangibles 41,130 ( 16,443 ) $ 24,687 41,130 ( 11,383 ) 29,747 Total $ 179,219 $ ( 81,141 ) $ 98,078 $ 181,478 $ ( 62,370 ) $ 119,108 Amortization expense associated with identifiable intangible assets was $ 19.8 million, $ 18.6 million and $ 16.4 million for the years ended December 31, 2024, 2023 and 2022, respectively. Annual estimated total amortization expense is $ 16.8 million, $ 15.1 million, $ 13.7 million, $ 12.2 million and $ 11.2 million for the years ended December 31, 2025 through 2029, respectively.

Capitalized Software, Furniture

Capitalized Software, Furniture, Equipment and Leasehold Improvements	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Abstract]
Capitalized Software, Furniture, Equipment and Leasehold Improvements	8. Capitalized Software, Furniture, Equipment and Leasehold Improvements Capitalized software development costs, furniture, equipment and leasehold improvements, net of accumulated depreciation and amortization, are comprised of the following: As of December 31, 2024 2023 (In thousands) Software development costs $ 307,722 $ 261,850 Computer hardware and related software 50,770 42,913 Office hardware 7,201 7,609 Furniture and fixtures 6,520 6,508 Leasehold improvements 31,386 31,214 403,599 350,094 Accumulated depreciation and amortization ( 296,301 ) ( 247,423 ) Total $ 107,298 $ 102,671 During the years ended December 31, 2024 and 2023, software development costs totaling $ 49.1 million and $ 43.1 million, respectively, were capitalized. Non-capitalized software costs and routine maintenance costs are expensed as incurred and are included in employee compensation and benefits and professional and consulting fees in the Consolidated Statements of Operations.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes The provision for income taxes consists of the following: Year Ended December 31, 2024 2023 2022 (In thousands) Current: Federal $ 48,337 $ 49,028 $ 52,865 State and local 9,695 4,047 20,716 Foreign 32,211 27,385 21,030 Total current provision 90,243 80,460 94,611 Deferred: Federal ( 2,884 ) ( 2,823 ) ( 5,830 ) State and local ( 573 ) ( 754 ) ( 1,350 ) Foreign ( 421 ) ( 2,238 ) 633 Total deferred provision ( 3,878 ) ( 5,815 ) ( 6,547 ) Provision for income taxes $ 86,365 $ 74,645 $ 88,064 Pre-tax income from U.S. operations was $ 235.8 million, $ 228.8 million and $ 236.4 million for the years ended December 31, 2024, 2023 and 2022, respectively. Pre-tax income from foreign operations was $ 124.7 million, $ 103.9 million and $ 101.9 million for the years ended December 31, 2024, 2023 and 2022, respectively. The difference between the U.S. federal statutory tax rate of 21.0 % and the Company’s effective tax rate is as follows: Year Ended December 31, 2024 2023 2022 U.S. federal statutory tax rate 21.0 % 21.0 % 21.0 % State and local taxes, net of federal benefit 1.9 0.8 4.6 Tax credits ( 1.3 ) ( 1.0 ) ( 0.4 ) Foreign rate differential detriment (benefit) 1.4 0.9 ( 0.1 ) Excess tax detriment (benefit) from stock-based compensation 0.4 0.1 ( 0.1 ) Other, net 0.6 0.6 1.0 Effective tax rate 24.0 % 22.4 % 26.0 % The following is a summary of the Company’s net deferred tax assets: As of December 31, 2024 2023 (In thousands) Deferred tax assets: Stock compensation expense $ 4,880 $ 4,441 Operating lease liabilities 15,753 17,128 Deferred compensation 2,700 2,596 Capitalized software development 3,130 791 Other 1,096 224 Total deferred tax assets 27,559 25,180 Valuation allowance — — Net deferred tax assets 27,559 25,180 Deferred tax liabilities: Depreciation ( 6,990 ) ( 8,617 ) Goodwill and intangible assets ( 5,307 ) ( 3,987 ) Operating lease right-of-use assets ( 12,515 ) ( 13,507 ) Other deferred tax liabilities — ( 276 ) Deferred tax asset (liability), net $ 2,747 $ ( 1,207 ) The Company is currently under a New York State income tax examination for tax years 2015 through 2020 and a New York City income tax examination for the tax years 2016 through 2018 . At this time, the Company cannot estimate when the examinations will conclude or the impact such examinations will have on the Company’s Consolidated Financial Statements, if any. Generally, other than New York City and State, the Company is no longer subject to tax examinations by tax authorities for years prior to 2020. A reconciliation of the Company’s unrecognized tax benefits is as follows: Year Ended December 31, 2024 2023 2022 (In thousands) Balance at beginning of year $ 3,130 $ 9,835 $ 15,089 Increase/(decrease) based on tax positions related to prior periods — — 160 (Decrease) related to settlements with taxing authorities ( 3,130 ) ( 6,705 ) ( 5,414 ) Balance at end of year $ — $ 3,130 $ 9,835 As of December 31, 2024, the Company had no unrecognized tax benefits recorded. During the years ended December 31, 2024, 2023 and 2022, the Company recognized gross expenses of $ 0.3 million, $ 1.6 million and $ 5.8 million, respectively, in penalties and interest. The Company had no accrued balances for the payment of interest and penalties as of December 31, 2024, and $ 2.6 million accrued for the payment of interest and penalties as of December 31, 2023. The Company will recognize any U.S. income tax expense the Company may incur on global intangible low-taxed income as income tax expense in the period in which the tax is incurred.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Equity Common Stock As of December 31, 2024 , the Company had 110,000,000 authorized shares of voting common stock and 10,000,000 authorized shares of non-voting common stock. Voting common stock entitles the holder to one vote per share of common stock held. The following is a summary of the changes in the Company’s outstanding shares of voting common stock: Year Ended December 31, 2024 2023 2022 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,900 37,648 37,919 Exercise of stock options 16 6 29 Issuance of restricted stock and performance shares, net of cancellations 125 97 66 Shares withheld for withholding tax payments ( 61 ) ( 81 ) ( 86 ) Repurchases ( 342 ) — ( 280 ) Reissuance of treasury stock 8 5 — Treasury stock used for acquisition — 225 — Outstanding shares of voting common stock at the end of year 37,646 37,900 37,648 The Board authorized the 2022 Repurchase Program and the 2024 Repurchase Program in January 2022 and August 2024, respectively. During the year ended December 31, 2024, the Company repurchased 341,477 shares of common stock under the Repurchase Programs at a cost of $ 75.0 million. As of December 31, 2024, the Company had $ 225.0 million of remaining capacity under the Repurchase Programs. Shares repurchased under the Repurchase Programs will be held in treasury for future use. Dividends During 2024, 2023 and 2022, the Company paid quarterly cash dividends of $ 0.74 per share, $ 0.72 per share and $ 0.70 per share, respectively. Any future declaration and payment of dividends will be at the sole discretion of the Board. The Board may take into account such matters as general business conditions, the Company’s financial results and condition, capital requirements, contractual obligations, and legal and regulatory restrictions on the payment of dividends to the Company’s stockholders or by the Company’s subsidiaries to their respective parent entities, and any such other factors as the Board may deem relevant.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	11. Stock-Based Compensation Plans The Company maintains the 2020 Plan which provides for the grant of Full Value Awards, stock options and other stock-based awards as incentives to encourage employees, consultants and non-employee directors to participate in the long-term success of the Company. As of December 31, 2024 , there were 2,562,436 shares available for grant under the 2020 Plan. Total stock-based compensation expense was as follows: Year Ended December 31, 2024 2023 2022 (In thousands) Employees Full Value Awards $ 27,607 $ 24,205 $ 24,593 Stock options 1,728 3,592 3,583 29,335 27,797 28,176 Non-employee directors Restricted stock and restricted stock units 1,512 1,393 1,688 Total stock-based compensation $ 30,847 $ 29,190 $ 29,864 The Company records stock-based compensation expense for employees in employee compensation and benefits and for non-employee directors in general and administrative expenses in the Consolidated Statements of Operations. Total stock-based compensation for employees includes $ 1.2 million, $ 0.9 million and $ 0.9 million of capitalized software development costs for the years ended December 31, 2024, 2023 and 2022, respectively. Stock Options The exercise price of each option granted is equal to the market price of the Company’s common stock on the date of grant. Generally, option grants have provided for vesting over a three-year period. Options generally expire in six years from the date of grant. The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model. The determination of fair value of share-based payment awards on the date of grant using an option-pricing model is affected by the Company’s stock price as well as assumptions regarding a number of complex and subjective variables, including the expected stock price volatility over the term of the awards, the risk-free interest rate, the expected dividend yield rate and the expected term. Expected volatilities are based on historical volatility of the Company’s stock. The risk-free interest rate is based on U.S. Treasury securities with a maturity value approximating the expected term of the option. The dividend yield rate is based on the expected annual dividends to be paid divided by the expected stock price. The expected term represents the period of time that options granted are expected to be outstanding based on actual and projected employee stock option exercise behavior. The weighted-average fair value for options granted during the years ended December 31, 2024, 2023 and 2022 were $ 77.16 , $ 123.47 and $ 101.38 , respectively. The following table represents the assumptions used for the Black-Scholes option-pricing model to determine the per share weighted-average fair value for options granted: Year Ended December 31, 2024 2023 2022 Expected life (years) 4.7 5.0 5.0 Risk-free interest rate 4.0 % 3.6 % 1.5 % Expected volatility 39.2 % 35.8 % 32.6 % Expected dividend yield 1.3 % 0.8 % 0.7 % The following table reports stock option activity during the years ended December 31, 2024, 2023 and 2022 and the intrinsic value as of December 31, 2024: Number Weighted-Average Exercise Price ($) Remaining Intrinsic Value ($) (In thousands) Outstanding at December 31, 2021 312,753 274.35 Granted 23,904 352.15 Canceled or forfeited ( 1,646 ) 421.08 Exercised ( 28,758 ) 157.08 Outstanding at December 31, 2022 306,253 290.65 Granted 13,908 358.53 Canceled or forfeited ( 551 ) 382.12 Exercised ( 5,653 ) 166.34 Outstanding at December 31, 2023 313,957 295.74 Granted 20,793 220.50 Canceled or forfeited ( 229,478 ) 276.79 Exercised ( 22,044 ) 205.28 1,314 Outstanding at December 31, 2024 83,228 353.14 3.2 115 Exercisable at December 31, 2024 46,710 411.47 2.1 — The intrinsic value is the amount by which the closing price of the Company’s common stock on December 31, 2024 of $ 226.04 or the price on the day of exercise exceeds the exercise price of the stock options multiplied by the number of shares. As of December 31, 2024 , there was $ 1.8 million of total unrecognized compensation cost related to unvested stock options. That cost is expected to be recognized over a weighted-average period of 1.5 years. Service-Based Restricted Stock and Restricted Stock Unit Awards Our annual compensation program includes share-based compensation awards as a component of certain employees’ total compensation. These awards generally vest ratably over a three-year period, subject to continued service to the Company. In addition, we grant share-based compensation awards in conjunction with certain new hires and for retention purposes. These awards generally vest over a three-year period. The Company also grants share-based compensation awards to its non-employee directors as part of such directors’ compensation. These awards generally vest on the earlier of the date of the Company’s next annual stockholders’ meeting or the one-year anniversary of the grant date, subject to continued service to the Company. Such share-based compensation awards are expensed over the requisite service period. Annual Performance-based Performance Stock Unit Awards The Company grants performance stock unit awards to certain executives and certain senior managers of the firm as a component of their total compensation and in conjunction with certain new hires and for retention purposes. Annual performance stock unit awards generally cliff-vest on the third anniversary of the grant date based on the certification of certain performance metrics and subject to the applicable employee’s continued service with the Company. In January 2022, February 2023 and February 2024, annual performance stock units were granted with a three-year performance period that will vest based on the level of achievement by the Company of certain predetermined metrics, including pre-tax adjusted operating margin, U.S. credit market share and revenue growth excluding U.S. credit for the following three fiscal years, including the year of grant. The final awarded payout for the awards granted in 2022, 2023 and 2024 will range from zero to 200 %. Subject to the grantee’s continued service, any performance stock unit award awarded to a participant will vest on the three-year anniversary of the grant date. Compensation expense for the three-year performance stock units is measured at the grant date and expensed over the requisite service period with performance target achievement assessed at the end of each reporting period. Other Performance Stock Unit Awards In March 2022, the Company’s Chief Information Officer received a one-time sign-on equity award consisting, in part, of a performance stock unit award with a target of 3,986 shares. The award will vest on March 1, 2025 after certification of the performance criteria, subject to his continued service through such date. Compensation expense for the Chief Information Officer award was measured at the grant date and will be expensed over the requisite service period with performance target achievement assessed at the end of each reporting period. In April 2023, in connection with his appointment to the position, the Company’s Chief Executive Officer received a one-time equity award consisting, in part, of a performance stock unit award with a target of 5,039 shares. The performance stock units vest 25 % on each of the third and fourth anniversaries of the grant date and 50 % on the fifth anniversary of the grant date, subject to certification of the performance criteria and his continued service through the respective vesting dates. Compensation expense for the Chief Executive Officer award was measured at the grant date and will be expensed over the requisite service period. In June 2024, the Company’s Chief Financial Officer received a one-time sign-on equity award consisting, in part, of a performance stock unit award with a target of 1,797 shares. The award will vest on June 3, 2027 after certification of the performance criteria, subject to her continued service through such date. Compensation expense for the Chief Financial Officer award was measured at the grant date and will be expensed over the requisite service period with performance target achievement assessed at the end of each reporting period. Performance Stock Unit Award Estimates The following table reports the Company’s performance payout estimates for three-year performance period awards as of December 31, 2024, as well as the target and maximum share payouts for each award date granted: Award Date Estimate Target Maximum January 31, 2022 7,771 17,844 35,688 March 1, 2022 1,736 3,986 7,972 February 15, 2023 11,060 17,607 35,214 February 15, 2024 31,681 30,811 61,622 June 3, 2024 1,797 1,797 3,594 Equity Grant Activity The following table reports Full Value Awards activity during the years ended December 31, 2024, 2023 and 2022: Number of Restricted Shares Weighted-Average Grant Date Fair Value Outstanding at December 31, 2021 162,610 $ 316.56 Granted 72,861 Performance share pay-out — Canceled ( 8,513 ) Vested ( 64,602 ) Outstanding at December 31, 2022 162,356 $ 321.04 Granted 90,242 Performance share pay-out 12,145 Canceled ( 5,272 ) Vested ( 98,927 ) Outstanding at December 31, 2023 160,544 $ 346.15 Granted 150,031 Performance share pay-out 4,739 Canceled ( 29,581 ) Vested ( 85,932 ) Outstanding at December 31, 2024 199,801 $ 276.74 As of December 31, 2024 , there was $ 39.6 million of total unrecognized compensation cost related to Full Value Awards. That cost is expected to be recognized over a weighted-average period of 1.7 years. Employee Stock Purchase Plan The Company maintains the MarketAxess Holdings Inc. 2022 Employee Stock Purchase Plan (the “ESPP”) pursuant to which a total of 121,221 shares of the Company’s Common Stock will be made available for purchase by employees. During the year ended December 31, 2024 , the Company issued 8,511 shares of common stock under the ESPP. As of December 31, 2024 , there were 108,055 shares available for purchase under the ESPP.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2024
Earnings Per Share [Abstract]
Earnings Per Share	12. Earnings Per Share The following table sets forth basic and diluted weighted average shares outstanding used to compute earnings per share: Year Ended December 31, 2024 2023 2022 (In thousands, except per share amounts) Basic weighted average shares outstanding 37,600 37,546 37,468 Dilutive effect of stock options and full value awards 72 108 175 Diluted weighted average shares outstanding 37,672 37,654 37,643 Basic earnings per share $ 7.29 $ 6.87 $ 6.68 Diluted earnings per share 7.28 6.85 6.65 Stock options and Full Value Awards totaling 329,810 shares, 306,678 shares and 310,447 shares for the years ended December 31, 2024, 2023 and 2022 , respectively, were excluded from the computation of diluted earnings per share because their effect would have been antidilutive. The computation of diluted shares can vary among periods due, in part, to the change in the average price of the Company’s common stock.

Credit Agreements and Short-ter

Credit Agreements and Short-term Financing	12 Months Ended
	Dec. 31, 2024
Debt Disclosure [Abstract]
Credit Agreements and Short-term Financing	13. Credit Agreements and Short-term Financing Credit Agreement On August 9, 2023, the Company entered into a new three-year revolving credit facility (the “Credit Agreement”) provided by a syndicate of lenders and JPMorgan Chase Bank, N.A., as administrative agent , which provides aggregate commitments totaling $ 750.0 million, including a revolving credit facility, a $ 5.0 million letter of credit sub-limit for standby letters of credit and a $ 380.0 million sub-limit for swingline loans. The Credit Agreement will mature on August 9, 2026 , with the Company’s option to request up to two additional 364 -day extensions at the discretion of each lender and subject to customary conditions. Subject to satisfaction of certain specified conditions, the Company is permitted to upsize the Credit Agreement by up to $ 375.0 million in total . As of December 31, 2024, the Company had $ 0.1 million in letters of credit outstanding and $ 749.9 million in available borrowing capacity under the Credit Agreement. Borrowings under the Credit Agreement will bear interest at a rate per annum equal to an alternate base rate or the adjusted term Secured Overnight Financing Rate (“SOFR”) rate, plus an applicable margin that varies with the Company’s consolidated total leverage ratio. The Credit Agreement requires that the Company satisfy certain covenants, including a requirement not to exceed a maximum consolidated total leverage ratio. The Company incurred $ 0.2 million and $ 0.1 million of interest expense under the Credit Agreement for the years ended December 31, 2024 and 2023, respectively. The Company also incurred $ 0.1 million and $ 0.3 million of interest expense under a previous credit agreement for the years ended December 31, 2023 and 2022, respectively. Uncommitted Collateralized Agreements In connection with their self-clearing operations, certain of the Company’s U.S. and U.K. operating subsidiaries maintain agreements with a settlement bank to allow the subsidiaries to borrow in the aggregate of up to $ 500.0 million on an uncommitted basis, collateralized by eligible securities pledged by the subsidiaries to the settlement bank, subject to certain haircuts. Borrowings under these agreements will bear interest at a base rate per annum equal to the higher of the upper range of the Federal Funds Rate, 0.25% or one-month SOFR, plus 1.00 %. The Company incurred $ 0.1 million of interest expense on borrowings under such agreements during the each of the years ended December 31, 2024 and 2023, and no interest expense on borrowings under such agreements during the year ended December 31, 2022. As of December 31, 2024 , the Company had no borrowings outstanding and up to $ 500.0 million in available uncommitted borrowing capacity under such agreements. Short-term Financing Under arrangements with their settlement banks, certain of the Company’s U.S. and U.K. operating subsidiaries may receive overnight financing in the form of bank overdrafts. The Company incurred interest expense on such overnight financing of $ 1.4 million, $ 0.7 million and $ 0.4 million during the years ended December 31, 2024, 2 023 and 2022, respectively. As of December 31, 2024 , the Company had no overdrafts payable outstanding.

Leases

Leases	12 Months Ended
	Dec. 31, 2024
Leases [Abstract]
Leases	14. Leases The Company has operating leases for corporate offices with initial lease terms ranging from one-year to 15 years. Certain leases contain options to extend the initial term at the Company’s discretion . The Company accounts for the option to extend when it is reasonably certain of being exercised. The Company’s lease agreements do not contain any material residual value guarantees, restrictions or covenants. The Company also has operating and finance leases for equipment with initial lease terms ranging from one-year to 5 years. The following table presents the components of operating lease expense for the years ended December 31, 2024, 2023 and 2022: Year Ended December 31, Lease cost: Classification 2024 2023 2022 (In thousands) Operating lease cost - office space Occupancy $ 11,034 $ 12,861 $ 13,015 Operating lease cost for subleased/assigned properties Other, net — — 469 Operating lease cost - equipment Technology and communications 390 98 — Variable lease costs Occupancy 3,327 237 96 Sublease income Other, net — — ( 405 ) Total operating lease cost $ 14,751 $ 13,196 $ 13,175 Finance lease expense was $ 0.1 million for the year ended December 31, 2024 . The Company determines whether an arrangement is, or includes, a lease at contract inception. Lease right-of-use assets and liabilities are recognized at commencement date and are initially measured based on the present value of lease payments over the defined lease term. As the Company’s leases do not provide an implicit rate, the Company used its incremental borrowing rate based on the information available at the adoption date in determining the present value of lease payments. The weighted average remaining lease term and weighted average discount rate are as follows: As of Lease Term and Discount Rate December 31, 2024 December 31, 2023 Weighted average remaining lease term (in years) - operating leases 8.8 9.6 Weighted average discount rate - operating leases 6.1 % 6.0 % Weighted average remaining lease term (in years) - finance leases 0.8 1.8 Weighted average discount rate - finance leases 7.2 % 7.2 % The following table presents the maturity of lease liabilities as of December 31, 2024: Operating Leases Finance Leases (In thousands) 2025 $ 12,699 88 2026 12,115 — 2027 9,286 — 2028 8,675 — 2029 8,992 — 2030 and thereafter 42,186 — Total lease payments 93,953 88 Less: imputed interest 21,299 3 Present value of lease liabilities $ 72,654 $ 85

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	15. Commitments and Contingencies Legal In the normal course of business, the Company and its subsidiaries included in the consolidated financial statements may be involved in various lawsuits, proceedings and regulatory examinations. The Company assesses its liabilities and contingencies in connection with outstanding legal proceedings, if any, utilizing the latest information available. For matters where it is probable that the Company will incur a material loss and the amount can be reasonably estimated, the Company will establish an accrual for the loss. Once established, the accrual will be adjusted to reflect any relevant developments. When a loss contingency is not both probable and estimable, the Company does not establish an accrual. Based on currently available information, the outcome of the Company’s outstanding matters is not expected to have a material adverse impact on the Company’s financial position. It is not presently possible to determine the ultimate exposure to these matters and there is no assurance that the resolution of the outstanding matters will not significantly exceed any reserves accrued by the Company. Other The Company, through certain of its subsidiaries, executes securities transactions between its institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller in trades. The Company’s operating subsidiaries settle such transactions pursuant to their self-clearing operations or through the use of third-party clearing brokers or settlement agents. Settlement typically occurs within one to two trading days after the trade date. Cash settlement of the transaction occurs upon receipt or delivery of the underlying instrument that was traded. Under both the self-clearing and the third-party clearing models, the Company may be exposed to credit risk in the event a counterparty does not fulfill its obligation to complete a transaction or if there is an error in executing a matched principal transaction. Pursuant to the terms of the securities clearing agreements, each third-party clearing broker has the right to charge the Company for any losses they suffer resulting from a counterparty’s failure on any of the Company’s trades. The Company did not record any liabilities or losses with regard to counterparty failures for the years ended December 31, 2024, 2023 and 2022 respectively. In the normal course of business, the Company enters into contracts that contain a variety of representations, warranties and indemnification provisions. The Company’s maximum exposure under these arrangements is unknown, as this would involve future claims that may be made against the Company that have not yet occurred. However, based on experience, the Company expects the risk of loss to be remote .

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2024
Segment Reporting [Abstract]
Segment and Geographic Information	16. Segment and Geographic Information The Company’s end-to-end trading solutions comprise one reportable segment. The Company’s end-to-end trading solutions segment includes the operation of electronic platforms for the trading of fixed-income and other securities and related data, analytics, compliance tools, post-trade services and technology services. The Company derives revenue primarily in North America and Europe and manages its business activities on a consolidated basis. The Company considers its operations to constitute a single business segment due to the highly integrated nature of these products and services within the trading lifecycle, the use of a single inter-connected suite of technology solutions underlying all services, the financial markets in which the Company competes and the Company’s worldwide business activities. The accounting policies of the Company's reportable segment are the same as those described in the summary of significant accounting policies. The CODM assesses performance of the Company overall and decides how to allocate resources based on net income that is reported on the consolidated statement of operations as net income. The measure of segment assets is reported on the consolidated statement of financial condition as total assets. The Company’s CODM is its Chief Executive Office r. The CODM uses net income to evaluate income generated from segment assets in deciding whether to reinvest profits into the Company’s end-to-end trading solutions or into other areas, such as for acquisitions or to pay dividends. Net income is used to monitor budget versus actual results. The significant segment expenses and net income reviewed by the CODM conform to the presentation of such items in the consolidated statements of operations. For the years ended December 31, 2024, 2023 and 2022, the U.K. was the only individual foreign country in which the Company had operations that accounted for 10.0 % or more of the total revenues or total long-lived assets. Revenues and long-lived assets are attributed to a geographic area based on the location of the client trading activity and receipt of services. Long-lived assets are defined as furniture, equipment, leasehold improvements and capitalized software . Revenues for the years ended December 31, 2024, 2023 and 2022 and long-lived assets as of December 31, 2024 and 2023 were as follows: Year Ended December 31, 2024 2023 2022 (In thousands) Revenues United States $ 568,595 $ 523,683 $ 510,802 United Kingdom 161,838 147,019 126,862 Other 86,664 81,845 80,636 Total $ 817,097 $ 752,547 $ 718,300 As of December 31, 2024 December 31, 2023 (In thousands) Long-lived assets, as defined United States $ 92,983 $ 87,502 United Kingdom 12,683 14,713 Other 1,632 456 Total $ 107,298 $ 102,671

Retirement and Deferred Compens

Retirement and Deferred Compensation Plans	12 Months Ended
	Dec. 31, 2024
Retirement Benefits [Abstract]
Retirement and Deferred Compensation Plans	17. Retirement and Deferred Compensation Plans The Company, through its U.S. and U.K. subsidiaries, offers its employees the opportunity to invest in defined contribution plans. For the years ended December 31, 2024, 2023 and 2022 , the Company contributed $ 11.7 million, $ 7.6 million and $ 6.1 million, respectively, to the plans. The Company offers a non-qualified deferred cash incentive plan to certain officers and other employees. Under the plan, eligible employees may defer up to 100 % of their annual cash incentive pay. The Company has elected to fund its deferred compensation obligations through a rabbi trust. The rabbi trust is subject to creditor claims in the event of insolvency, but such assets are not available for general corporate purposes. Assets held in the rabbi trust are invested in mutual funds, as selected by the participants, which are designated as trading securities and carried at fair value. As of December 31, 2024 and 2023, the fair value of the mutual fund investments and deferred compensation obligations was $ 11.1 million and $ 10.5 million, respectively. Changes in the fair value of securities held in the rabbi trust and offsetting increases or decreases in the deferred compensation obligation are recognized in other, net in the Company’s Consolidated Statements of Operations.

Cash and Cash Equivalents and R

Cash and Cash Equivalents and Restricted Cash	12 Months Ended
	Dec. 31, 2024
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents and Restricted Cash	18. Cash and Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash and cash equivalents together with restricted or segregated cash as reported within the Consolidated Statements of Financial Condition to the sum of the same such amounts shown in the Consolidated Statements of Cash Flows: As of December 31, Statement of Financial Condition Location 2024 2023 2022 (In thousands) Cash and cash equivalents Cash and cash equivalents $ 544,478 $ 451,280 $ 430,746 Cash segregated for regulatory Cash segregated under federal 47,107 45,122 50,947 Restricted cash deposits with clearing Receivables from broker-dealers, 107,652 115,151 88,923 Other cash deposits Prepaid expenses and other assets 1,222 119 2,048 Total $ 700,459 $ 611,672 $ 572,664

Parent Company Information

Parent Company Information	12 Months Ended
	Dec. 31, 2024
Condensed Financial Information Disclosure [Abstract]
Parent Company Information	19. Parent Company Information The following tables present Parent Company-only financial information that should be read in conjunction with the consolidated financial statements of the Company. MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Financial Condition As of December 31, 2024 December 31, 2023 (In thousands) ASSETS Cash and cash equivalents $ 94,332 $ 65,951 Investments, at fair value 60,735 30,225 Accounts receivable 1,397 1,923 Receivable from subsidiaries 22,606 18,010 Intangible assets, net of accumulated amortization 18 21 Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization 15,617 17,644 Operating lease right-of-use assets 51,416 55,113 Investments in subsidiaries 1,179,524 1,140,798 Prepaid expenses and other assets 40,903 45,140 Income and other tax receivable 8,253 7,674 Total assets $ 1,474,801 $ 1,382,499 LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities Accrued employee compensation 9,707 $ 8,589 Income and other tax liabilities 722 3,000 Accounts payable, accrued expenses and other liabilities 10,646 8,212 Operating lease liabilities 65,066 69,735 Total liabilities 86,141 89,536 Stockholders’ equity Preferred stock — — Series A Preferred Stock — — Common stock voting 123 123 Common stock non-voting — — Additional paid-in capital 350,701 333,292 Treasury stock ( 333,369 ) ( 260,298 ) Retained earnings 1,405,904 1,244,216 Accumulated other comprehensive loss ( 34,699 ) ( 24,370 ) Total stockholders’ equity 1,388,660 1,292,963 Total liabilities and stockholders’ equity $ 1,474,801 $ 1,382,499 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations Year Ended December 31, 2024 2023 2022 (In thousands) Revenues $ 246,600 $ 270,700 $ 257,200 Expenses Employee compensation and benefits 12,091 13,938 17,655 Depreciation and amortization 2,186 2,153 2,136 Professional and consulting fees 6,149 5,828 5,528 General and administrative 1,660 2,301 3,081 Total expenses 22,086 24,220 28,400 Operating income 224,514 246,480 228,800 Other income (expense) Interest income 4,615 3,557 272 Interest expense ( 167 ) ( 155 ) ( 271 ) Equity in earnings of unconsolidated affiliate 1,395 735 1,126 Other, net ( 5,088 ) ( 369 ) ( 2,633 ) Total other income (expense) 755 3,768 ( 1,506 ) Income before income taxes and equity in undistributed earnings of subsidiaries 225,269 250,248 227,294 Benefit from income taxes ( 6,550 ) ( 5,586 ) ( 7,710 ) Income before equity in undistributed income of subsidiaries 231,819 255,834 235,004 Equity in undistributed income of subsidiaries 42,362 2,221 15,220 Net income 274,181 258,055 250,224 Other comprehensive income (loss), net ( 10,329 ) 13,327 ( 24,367 ) Comprehensive income $ 263,852 $ 271,382 $ 225,857 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2024 2023 2022 (In thousands) Cash flows from operating activities Net income $ 274,181 $ 258,055 $ 250,224 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 2,186 2,153 2,136 Amortization of operating lease right-of-use assets 3,697 3,361 3,347 Stock-based compensation expense 7,130 9,725 12,554 Deferred taxes 397 101 ( 5,076 ) Equity in undistributed income of subsidiaries ( 42,362 ) ( 2,221 ) ( 15,220 ) Other 4,304 ( 4,675 ) 441 Changes in operating assets and liabilities: (Increase)/decrease in accounts receivable 526 ( 1,154 ) ( 769 ) Decrease in receivable from subsidiaries 12,694 5,474 7,931 Decrease/(increase) in prepaid expenses and other assets 304 1,296 ( 1,175 ) (Increase)/decrease in mutual funds held in rabbi trust ( 94 ) ( 189 ) 984 (Decrease)/increase in accrued employee compensation 1,118 ( 1,104 ) ( 1,372 ) (Increase)/decrease in income and other tax receivables ( 579 ) 3,800 ( 9,711 ) Increase/(decrease) increase in income and other tax liabilities ( 2,278 ) 2,287 62 (Decrease)/increase in accounts payable, accrued expenses and other liabilities 4,809 ( 861 ) 443 (Decrease) in operating lease liabilities ( 4,669 ) ( 3,624 ) ( 3,689 ) Net cash provided by operating activities 261,364 272,424 241,110 Cash flows from investing activities Acquisition of business — ( 81,161 ) — Acquisition of equity method investment — — ( 34,400 ) Investments in subsidiaries ( 30 ) ( 10,058 ) ( 8,326 ) Available-for-sale investments Proceeds from maturities and sales 12,440 4,454 — Purchases ( 42,810 ) ( 28,818 ) — Purchases of furniture, equipment and leasehold improvements ( 156 ) ( 239 ) ( 96 ) Net cash (used in) investing activities ( 30,556 ) ( 115,822 ) ( 42,822 ) Cash flows from financing activities Cash dividend on common stock ( 112,697 ) ( 109,658 ) ( 105,942 ) Exercise of stock options 2,988 940 672 Withholding tax payments on Full Value Awards vesting and stock option exercises ( 16,194 ) ( 25,839 ) ( 23,404 ) Repurchases of common stock ( 75,474 ) — ( 87,540 ) Proceeds from short-term borrowings 100,000 100,000 100,000 Repayments of short-term borrowings ( 100,000 ) ( 100,000 ) ( 100,000 ) Net cash (used in) financing activities ( 201,377 ) ( 134,557 ) ( 216,214 ) Effect of exchange rate changes on cash and cash equivalents — ( 3 ) 15 Cash and cash equivalents including restricted cash Net increase (decrease) for the period 29,431 22,042 ( 17,911 ) Beginning of period 65,951 43,909 61,820 End of period $ 95,382 $ 65,951 $ 43,909 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows (Continued) Year Ended December 31, 2024 2023 2022 (In thousands) Supplemental cash flow information: Cash paid for income taxes $ 53,999 $ 55,784 $ 65,764 Cash paid for interest 167 35 271 Non-cash investing and financing activity: Exercise of stock options - cashless $ 1,735 $ — $ 3,845 Right-of-use assets obtained in exchange for operating lease liabilities — 1,072 — Treasury stock used for acquisition of business — 43,841 —

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company defines cash equivalents as short-term interest-bearing investments with maturities at the time of purchase of three months or less.
Investments	Investments The Company determines the appropriate classification of securities at the time of purchase which are recorded in the Consolidated Statements of Financial Condition on the trade date. Securities are classified as available-for-sale or trading. Available-for-sale investments are carried at fair value with unrealized gains or losses reported in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition and realized gains or losses reported in other, net in the Consolidated Statements of Operations. Trading investments include U.S. Treasuries and are carried at fair value, with realized and unrealized gains or losses included in other, net in the Consolidated Statements of Operations. The Company assesses whether an impairment loss on its available-for-sale debt securities has occurred due to declines in fair value or other market conditions. When the amortized cost basis of an available-for-sale debt security exceeds its fair value, the security is deemed to be impaired. The portion of an impairment related to credit losses is determined by comparing the present value of cash flows expected to be collected from the security with the amortized cost basis of the security and is recorded as a charge in the Consolidated Statements of Operations. The remainder of an impairment is recognized in accumulated other comprehensive loss if the Company does not intend to sell the security and it is more likely than not that the Company will not be required to sell the security prior to recovery.
Fair Value Financial Instruments	Fair Value Financial Instruments Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” A three-tiered hierarchy for determining fair value has been established that prioritizes inputs to valuation techniques used in fair value calculations. The three levels of inputs are defined as Level 1 (unadjusted quoted prices for identical assets or liabilities in active markets), Level 2 (inputs that are observable in the marketplace other than those inputs classified in Level 1) and Level 3 (inputs that are unobservable in the marketplace). The Company’s financial assets and liabilities measured at fair value on a recurring basis consist of its money market funds, trading securities, available-for-sale securities and foreign currency forward contracts. All other financial instruments are short-term in nature and the carrying amounts reported on the Consolidated Statements of Financial Condition approximate fair value.
Receivables from and Payables to Broker- dealers, Clearing Organizations and Customers	Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers Receivables from broker-dealers, clearing organizations and customers include amounts receivable for securities not delivered by the Company to the purchaser by the settlement date (“securities failed-to-deliver”) and cash deposits held at clearing organizations and clearing brokers to facilitate the settlement and clearance of matched principal transactions. Payables to broker-dealers, clearing organizations and customers include amounts payable for securities not received by the Company from a seller by the settlement date (“securities failed-to-receive”). Securities failed-to-deliver and securities failed-to-receive for transactions executed on a matched principal basis where the Company serves as a counterparty to both the buyer and the seller are recorded on a settlement date basis. The Company presents its securities failed-to-deliver and securities failed-to-receive balances on a net-by-counterparty basis within receivables from and payables to broker-dealers, clearing organizations and customers. The difference between the Company’s trade-date receivables and payables for unsettled matched principal transactions reflects commissions earned and is recorded within accounts receivable, net on a trade date basis.
Allowance for Credit Losses	Allowance for Credit Losses All accounts receivable have contractual maturities of less than one year and are derived from trading-related fees and commissions and revenues from products and services. The Company continually monitors collections and payments from its customers and maintains an allowance for doubtful accounts. The allowance for credit losses is based on the estimated expected credit losses in accounts receivable, as determined from a review of aging schedules, past due balances, historical collection experience and other specific collection issues that have been identified. Account balances are grouped for evaluation based on various risk characteristics, including billing type, legal entity, and geographic region. Additions to the allowance for credit losses are charged to bad debt expense, which is included in general and administrative expense in the Company’s Consolidated Statements of Operations. Balances that are determined to be uncollectable are written off against the allowance for credit losses. The allowance for credit losses was $ 1.0 million and $ 0.6 million as of December 31, 2024 and 2023 , respectively. The provision for bad debts was $ 0.8 million, $ 0.4 million and $ 0.6 million for the years ended December 31, 2024, 2023 and 2022, respectively. Write-offs and other charges against the allowance for credit losses were $ 0.4 million, $ 0.3 million and $ 0.1 million for the years ended December 31, 2024, 2023 and 2022, respectively.
Depreciation and Amortization	Depreciation and Amortization Fixed assets are carried at cost less accumulated depreciation. The Company uses the straight-line method of depreciation over three to seven years . The Company amortizes leasehold improvements on a straight-line basis over the lesser of the life of the improvement or the remaining term of the lease.
Software Development Costs	Software Development Costs The Company capitalizes certain costs associated with the development of internal use software, including, among other items, employee compensation and related benefits and third-party consulting costs at the point at which the conceptual formulation, design and testing of possible software project alternatives have been completed. Once the product is ready for its intended use, such costs are amortized on a straight-line basis over three to five years . The Company reviews the amounts capitalized for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable.
Cloud Computing Costs	Cloud Computing Costs The Company capitalizes certain costs associated with cloud computing arrangements, including, among other items, vendor software development costs billed to us that are part of the application development stage. These costs are recorded as a prepaid asset on the Consolidated Statements of Financial Condition and are amortized over the period of the hosting service contract, which ranges from one to five years . The Company reviews the amounts capitalized for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable.
Foreign Currency Translation and Forward Contracts	Foreign Currency Translation and Forward Contracts Assets and liabilities denominated in foreign currencies are translated using exchange rates at the end of the period; revenues and expenses are translated at average monthly rates. Gains and losses on foreign currency translation are a component of accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Transaction gains and losses are recorded in other, net in the Consolidated Statements of Operations. The Company enters into foreign currency forward contracts to economically hedge its foreign currency transaction gains and losses. Realized and unrealized gains and losses on these forward contracts are included in other, net in the Consolidated Statements of Operations. The Company records the fair value of the forward contract asset in prepaid expenses and other assets or the fair value of the forward contract liability in accounts payable, accrued expenses and other liabilities in the Consolidated Statements of Financial Condition.
Revenue Recognition	Revenue Recognition The Company’s classification of revenues in the Consolidated Statements of Operations represents revenues from contracts with customers disaggregated by type of revenue. The Company has four revenue streams as described below. Commission Revenue – The Company charges its broker-dealer clients variable transaction fees for trades executed on its platforms and, under certain plans, distribution fees or monthly minimum fees to use the platforms for a particular product area. Variable transaction fees are recognized on a trade date basis, are generally calculated as a percentage of the notional dollar volume of bonds traded on the platforms and vary based on the type, size, yield and maturity of the bond traded, as well as individual client incentives. Bonds that are more actively traded or that have shorter maturities generally generate lower commissions, while bonds that are less actively traded or that have longer maturities generally command higher commissions. Under the Company’s disclosed trading transaction fee plans, variable transaction fees, distribution fees and unused monthly fee commitments are invoiced and recorded on a monthly basis. For Open Trading trades that the Company executes between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller, the Company earns its commission through the difference in price between the two trades. The commission is collected upon settlement of the trade, which typically occurs within one to two trading days after the trade date. For the majority of the Company’s U.S. Treasury matched principal trades, commissions are invoiced and recorded on a monthly basis. Following the Pragma Acquisition in the fourth quarter of 2023, the Company also earns other commissions on equities and foreign exchange products for algorithmic trading services. These fees incorporate variable transaction fees, which are calculated as a percentage of the notional dollar volume traded and are billed on a monthly basis. The following table presents commission revenue by fee type: Year Ended December 31, 2024 2023 2022 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 361,252 $ 323,038 $ 321,603 Open Trading – matched principal trading 177,966 178,517 175,440 U.S. government bonds - matched principal trading 19,310 15,222 16,978 Other 20,016 4,979 — Total variable transaction fees 578,544 521,756 514,021 Distribution fees and unused minimum fees 133,166 141,208 127,162 Total commissions $ 711,710 $ 662,964 $ 641,183 Information services – Information services includes data licensed to the Company’s broker-dealer clients, institutional investor clients and data-only subscribers; professional and consulting services; technology software licenses; and maintenance and support services. The nature and timing of each performance obligation may vary as these contracts are either subscription-based services transferred over time, and may be net of volume-based discounts, or one-time services that are transferred at a point in time. Revenues for services transferred over time are recognized ratably over the contract period as the Company’s performance obligation is met, whereas revenues for services transferred at a point in time are recognized in the period the services are provided. Customers are generally billed monthly, quarterly, or annually; revenues billed in advance are deferred and recognized ratably over the contract period. The following table presents information services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Information services revenue by timing Services transferred over time $ 49,560 $ 45,102 $ 38,452 Services transferred at a point in time 980 1,281 862 Total information services revenues $ 50,540 $ 46,383 $ 39,314 Post-trade services – Post-trade services revenue is generated from regulatory transaction reporting, trade publication and post-trade matching services. Customers are generally billed monthly in arrears and revenue is recognized in the period transactions are processed. Revenues billed in advance are deferred and recognized ratably over the contract period. The Company also generates one-time implementation fees for onboarding clients, which are invoiced and recognized in the period the implementation is completed. The following table presents post-trade services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Post-trade services revenue by timing Services transferred over time $ 42,170 $ 40,061 $ 36,835 Services transferred at a point in time 317 117 42 Total post-trade services revenues $ 42,487 $ 40,178 $ 36,877 Technology services – Technology services revenue primarily includes technology services revenue generated by Pragma and revenue from telecommunications line charges to broker-dealer clients. Customers may be billed monthly or quarterly in arrears or in advance, and revenue is recognized in the period transactions are processed. Revenues billed in advance are deferred and recognized ratably over the contract period. The following table presents technology services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Technology services revenue by timing Services transferred over time $ 12,334 $ 3,021 $ 926 Services transferred at a point in time 26 1 - Total technology services revenues $ 12,360 $ 3,022 $ 926 Contract liabilities consist of deferred revenues that the Company records when cash payments are received or due in advance of services to be performed. Deferred revenues are included in accounts payable, accrued expenses and other liabilities on the Consolidated Statements of Financial Condition. The revenue recognized from contract liabilities and the remaining balance is shown below: December 31, 2023 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2024 (In thousands) Information services $ 3,049 $ 14,948 $ ( 14,695 ) $ — $ 3,302 Post-trade services 923 20,436 ( 20,060 ) ( 13 ) 1,286 Technology services 567 8,213 ( 8,365 ) — 415 Total deferred revenue $ 4,539 $ 43,597 $ ( 43,120 ) $ ( 13 ) $ 5,003 The majority of the Company’s information services and post-trade services contracts are short-term in nature with durations of less than one year. For contracts with original durations extending beyond one year, the aggregate amount of the transaction price allocated to remaining performance obligations was $ 47.0 million as of December 31, 2024 . The Company expects to recognize revenue associated with the remaining performance obligations over the next 46 months.
Stock-Based Compensation	Stock-Based Compensation The Company measures and recognizes compensation expense for all share-based payment awards based on their estimated fair values measured as of the grant date. These costs are recognized as an expense in the Consolidated Statements of Operations over the requisite service period, which is typically the vesting period, with an offsetting increase to additional paid-in capital. Forfeitures are recognized as they occur.
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recognized against deferred tax assets if it is more likely than not that such assets will not be realized in future years. Tax benefits for uncertain tax positions are recognized when it is more likely than not that the positions will be sustained upon examination based on their technical merits. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes in the Consolidated Statements of Operations. All tax effects related to share-based payments are recorded in the provision for income taxes in the periods during which the awards are exercised or vest.
Business Combinations, Goodwill and Intangible Assets	Business Combinations, Goodwill and Intangible Assets Business combinations are accounted for under the purchase method of accounting. The total cost of an acquisition is allocated to the underlying net assets based on their respective estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Determining the fair value of certain assets acquired and liabilities assumed requires judgment and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash flows, discount rates, revenue growth rates, customer attrition rates, royalty rates, obsolescence and asset lives. Intangible assets are valued using various methodologies, including the relief-from-royalty method and multi-period excess earnings method. The Company operates as a single reporting unit. Following an acquisition, goodwill no longer retains its identification with a particular acquisition, but instead becomes identifiable with the entire reporting unit. As a result, all of the fair value of the Company is available to support the value of goodwill. An impairment review of goodwill is performed on an annual basis, at year-end, or more frequently if circumstances change. Intangible assets with definite lives, including purchased technologies, customer relationships and other intangible assets, are amortized over their estimated useful lives which range from one to 15 years using either a straight-line or accelerated amortization method based on the pattern of economic benefit the Company expects to realize from such assets. Intangible assets are assessed for impairment when events or circumstances indicate the existence of a possible impairment.
Equity Investments and Consolidation	Equity Investments and Consolidation The Company evaluates equity investments for potential consolidation under the voting-interest or variable-interest models. The Company consolidates investees over which the Company determines it has control under the voting interest model, generally greater than 50% ownership, or for which the Company is the primary beneficiary under the variable-interest model. The Company uses the equity method of accounting when it exercises significant influence over the investee, but does not have operating control, generally between 20% and 50% ownership. Under the equity method of accounting, original investments are recorded at cost in prepaid expenses and other assets on the Consolidated Statements of Financial Condition and adjusted by the Company’s proportionate share of the investees’ undistributed earnings or losses. Equity investments are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the investment may not be recoverable.
Earnings Per Share	Earnings Per Share Basic earnings per share is computed by dividing the net income attributable to common stock by the weighted-average number of shares of common stock outstanding during the period. For purposes of computing diluted earnings per share, the weighted-average shares outstanding of common stock reflects the dilutive effect that could occur if convertible securities or other contracts to issue common stock were converted into or exercised for common stock.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2023, Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The ASU expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly reviewed by the chief operating decision maker (“CODM”) and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items and interim disclosures of a reportable segment’s profit or loss and assets. The ASU also requires the disclosure of the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. All disclosure requirements under ASU 2023-07 and existing segment disclosures in ASC 280, Segment Reporting are also required for public entities with a single reportable segment. The ASU is effective for the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and subsequent interim periods. The ASU must be applied retrospectively to all periods presented in the financial statements. The Company adopted this standard for the year ended December 31, 2024. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation and income taxes paid. The ASU is effective for the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025. The guidance may be applied on a prospective or retrospective basis and early adoption is permitted. Adoption of this ASU will result in additional disclosures, but will not have an impact on the Company’s consolidated statements of financial condition, operations and cash flows. In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses . The ASU primarily will require enhanced disclosures about certain types of expenses. The amendments in ASU 2024-03 are effective for fiscal years beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027, and may be applied either on a prospective or retrospective basis. The Company is currently evaluating the impact of the standard on its disclosures.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Summary of Commission Revenue by Fee Type	The following table presents commission revenue by fee type: Year Ended December 31, 2024 2023 2022 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 361,252 $ 323,038 $ 321,603 Open Trading – matched principal trading 177,966 178,517 175,440 U.S. government bonds - matched principal trading 19,310 15,222 16,978 Other 20,016 4,979 — Total variable transaction fees 578,544 521,756 514,021 Distribution fees and unused minimum fees 133,166 141,208 127,162 Total commissions $ 711,710 $ 662,964 $ 641,183
Summary of Information Services Revenue by Timing of Recognition	The following table presents information services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Information services revenue by timing Services transferred over time $ 49,560 $ 45,102 $ 38,452 Services transferred at a point in time 980 1,281 862 Total information services revenues $ 50,540 $ 46,383 $ 39,314
Summary of Post-Trade Services Revenue by Timing of Recognition	The following table presents post-trade services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Post-trade services revenue by timing Services transferred over time $ 42,170 $ 40,061 $ 36,835 Services transferred at a point in time 317 117 42 Total post-trade services revenues $ 42,487 $ 40,178 $ 36,877
Summary of Technology Services Revenue by Timing of Recognition	The following table presents technology services revenue by timing of recognition: Year Ended December 31, 2024 2023 2022 (In thousands) Technology services revenue by timing Services transferred over time $ 12,334 $ 3,021 $ 926 Services transferred at a point in time 26 1 - Total technology services revenues $ 12,360 $ 3,022 $ 926
Summary of Revenue Recognized from Contract Liabilities and Remaining Balance	The revenue recognized from contract liabilities and the remaining balance is shown below: December 31, 2023 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2024 (In thousands) Information services $ 3,049 $ 14,948 $ ( 14,695 ) $ — $ 3,302 Post-trade services 923 20,436 ( 20,060 ) ( 13 ) 1,286 Technology services 567 8,213 ( 8,365 ) — 415 Total deferred revenue $ 4,539 $ 43,597 $ ( 43,120 ) $ ( 13 ) $ 5,003

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2024
Fair Value Disclosures [Abstract]
Valuation of Company's Assets and Liabilities Measured at Fair Value	The following table summarizes the valuation of the Company’s assets and liabilities measured at fair value as categorized based on the hierarchy described in Note 2: Level 1 Level 2 Level 3 Total (In thousands) As of December 31, 2024 Assets Money market funds $ 55,473 $ — $ — $ 55,473 Securities available-for-sale Corporate debt — 55,108 — 55,108 Trading securities U.S. Treasuries — 99,045 — 99,045 Mutual funds held in rabbi trust — 11,107 — 11,107 Total assets $ 55,473 $ 165,260 $ — $ 220,733 Liabilities Foreign currency forward position — 936 — 936 Total liabilities $ — $ 936 $ — $ 936 As of December 31, 2023 Assets Money market funds $ 18,634 $ — $ — $ 18,634 Securities available-for-sale Corporate debt — 24,694 — 24,694 Trading securities U.S. Treasuries — 99,682 — 99,682 Mutual funds held in rabbi trust — 10,485 — 10,485 Foreign currency forward position — 1,901 — 1,901 Total assets $ 18,634 $ 136,762 $ — $ 155,396
Carrying Value of Financial Asset and Liability Not Measured at Fair Value	The table below presents the carrying value, fair value and fair value hierarchy category of the Company’s financial assets and liabilities that are not measured at fair value on the Consolidated Statements of Financial Condition. The carrying values of the Company’s financial assets and liabilities not measured at fair value categorized in the fair value hierarchy as Level 1 and Level 2 approximate fair value due to the short-term nature of the underlying assets and liabilities. Carrying Value Fair Value Level 1 Level 2 Level 3 Total (In thousands) As of December 31, 2024 Financial assets not measured at fair value: Cash $ 489,005 $ 489,005 $ 489,005 $ — $ — $ 489,005 Cash segregated under federal regulations 47,107 47,107 47,107 — — 47,107 Accounts receivable, net of allowance 91,845 91,845 — 91,845 — 91,845 Receivables from broker-dealers, clearing 357,728 357,728 107,652 250,076 — 357,728 Total $ 985,685 $ 985,685 $ 643,764 $ 341,921 $ — $ 985,685 Financial liabilities not measured at fair value: Payables to broker-dealers, clearing $ 218,845 $ 218,845 $ — $ 218,845 $ — $ 218,845 As of December 31, 2023 Financial assets not measured at fair value: Cash $ 432,646 $ 432,646 $ 432,646 $ — $ — $ 432,646 Cash segregated under federal regulations 45,122 45,122 45,122 — — 45,122 Accounts receivable, net of allowance 89,839 89,839 — 89,839 — 89,839 Receivables from broker-dealers, clearing 687,936 687,936 115,151 572,785 — 687,936 Total $ 1,255,543 $ 1,255,543 $ 592,919 $ 662,624 $ — $ 1,255,543 Financial liabilities not measured at fair value: Payables to broker-dealers, clearing $ 537,398 $ 537,398 $ — $ 537,398 $ — $ 537,398
Summary of Foreign Currency Forward Contracts	The following table summarizes the Company’s foreign currency forward position: As of December 31, 2024 December 31, 2023 (In thousands) Notional value $ 64,454 $ 61,858 Fair value of notional 63,518 63,759 Fair value of the (liability)/asset $ ( 936 ) $ 1,901
Summary of Realized and Unrealized Gains and Losses on Foreign Currency Forward Contracts	The following table summarizes the realized and unrealized gains and losses on foreign currency forward contracts: Year Ended December 31, 2024 2023 2022 (In thousands) Unrealized gain/(loss) $ ( 2,838 ) $ 3,590 ( 1,688 ) Realized gain/(loss) 1,148 ( 1,470 ) $ 802 Total gain/(loss) $ ( 1,690 ) $ 2,120 $ ( 886 )
Summary of Company's Investments	The following table summarizes the Company’s investments: Amortized Gross Gross Fair (In thousands) As of December 31, 2024 Securities available-for-sale Corporate debt $ 55,447 $ 88 $ ( 427 ) $ 55,108 Trading securities U.S. Treasuries 100,484 86 ( 1,525 ) 99,045 Mutual funds held in rabbi trust 10,212 900 ( 5 ) 11,107 Total investments $ 166,143 $ 1,074 $ ( 1,957 ) $ 165,260 As of December 31, 2023 Securities available-for-sale Corporate debt $ 24,705 $ 55 $ ( 66 ) $ 24,694 Trading securities U.S. Treasuries 99,236 446 — 99,682 Mutual funds held in rabbi trust 10,962 172 ( 649 ) 10,485 Total investments $ 134,903 $ 673 $ ( 715 ) $ 134,861
Summary of Companies unrealized and realized gains and losses on investments	The following table summarizes the Company’s unrealized and realized gains and losses on investments: Year Ended December 31, 2024 2023 2022 (In thousands) Unrealized gains/(losses) Securities available-for-sale Corporate debt $ ( 328 ) $ ( 11 ) $ — Trading securities U.S. Treasuries ( 1,025 ) 446 ( 534 ) Mutual funds held in rabbi trust 1,372 1,284 ( 2,091 ) Total investments $ 19 $ 1,719 $ ( 2,625 ) Realized gains/(losses) Securities available-for-sale Corporate debt $ 4 $ ( 11 ) $ — Trading securities Mutual funds held in rabbi trust ( 328 ) ( 138 ) — Total investments $ ( 324 ) $ ( 149 ) $ — Liabilities: Securities sold, not yet purchased $ 174 $ — $ —
Summary of Fair Value of Investments Based upon Contractual Maturities	The following table summarizes the fair value of the Company’s corporate debt and U.S. Treasury investments based upon the contractual maturities: Less than one year Due in 1 - 5 years Total (In thousands) As of December 31, 2024 Securities available-for-sale Corporate debt $ 9,346 $ 45,762 $ 55,108 Trading securities U.S. Treasuries 49,978 49,067 99,045 Total $ 59,324 $ 94,829 $ 154,153 As of December 31, 2023 Securities available-for-sale Corporate debt $ 10,727 $ 13,967 $ 24,694 Trading securities U.S. Treasuries 49,756 49,926 99,682 Total $ 60,483 $ 63,893 $ 124,376
Summary of Fair Values and Unrealized Losses on Investments	The following table provides fair values and unrealized losses on the Company’s available-for-sale investments and the aging of securities’ continuous unrealized loss position: Less than Twelve Months Twelve Months or More Total Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses (In thousands) As of December 31, 2024 Corporate debt $ 38,041 $ ( 426 ) $ 1,226 $ ( 1 ) $ 39,267 $ ( 427 ) As of December 31, 2023 Corporate debt $ 17,658 $ ( 66 ) $ — $ — $ 17,658 $ ( 66 )

Receivables from and Payables_2

Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers (Tables)	12 Months Ended
	Dec. 31, 2024
Due to and from Broker-Dealers and Clearing Organizations [Abstract]
Schedule of Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers	Receivables from and payables to broker-dealers, clearing organizations and customers consisted of the following: As of December 31, 2024 December 31, 2023 Receivables from broker-dealers, clearing organizations and customers: (In thousands) Securities failed-to-deliver – broker-dealers and clearing organizations $ 109,307 $ 282,125 Securities failed-to-deliver – customers 136,424 284,322 Cash deposits with clearing organizations and broker-dealers 107,652 115,151 Other 4,345 6,338 Total $ 357,728 $ 687,936 Payables to broker-dealers, clearing organizations and customers: Securities failed-to-receive – broker-dealers and clearing organizations $ 158,694 $ 125,022 Securities failed-to-receive – customers 51,916 405,186 Other 8,235 7,190 Total $ 218,845 $ 537,398

Acquisitions and Equity Inves_2

Acquisitions and Equity Investments (Tables)	12 Months Ended
	Dec. 31, 2024
Business Combinations [Abstract]
Summary of Purchase Price Allocation	The purchase price allocation is as follows (in thousands): Purchase price $ 125,002 Less: acquired cash ( 2,685 ) Purchase price, net of acquired cash 122,317 Intangible assets ( 38,900 ) Accounts receivable ( 2,637 ) Prepaid expenses and other assets ( 4,181 ) Accounts payable, accrued expenses and other liabilities 5,318 Goodwill $ 81,917
Summary of Fair Value of Acquired Intangible Assets	The fair values of the intangible assets acquired are as follows (in thousands, except for useful lives): Costs Useful Lives Developed technology $ 28,500 7 years Customer relationships 9,200 15 years Tradename - finite life 1,200 15 years Total $ 38,900

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Company's Intangible Assets	Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2024 December 31, 2023 Cost Accumulated Net carrying Cost Accumulated Net carrying (In thousands) Customer relationships $ 138,089 $ ( 64,698 ) $ 73,391 $ 140,348 $ ( 50,987 ) $ 89,361 Technology and other intangibles 41,130 ( 16,443 ) $ 24,687 41,130 ( 11,383 ) 29,747 Total $ 179,219 $ ( 81,141 ) $ 98,078 $ 181,478 $ ( 62,370 ) $ 119,108

Capitalized Software, Furnitu_2

Capitalized Software, Furniture, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Abstract]
Capitalized Software Development Costs, Furniture, Equipment and Leasehold Improvements, Net of Accumulated Depreciation and Amortization	Capitalized software development costs, furniture, equipment and leasehold improvements, net of accumulated depreciation and amortization, are comprised of the following: As of December 31, 2024 2023 (In thousands) Software development costs $ 307,722 $ 261,850 Computer hardware and related software 50,770 42,913 Office hardware 7,201 7,609 Furniture and fixtures 6,520 6,508 Leasehold improvements 31,386 31,214 403,599 350,094 Accumulated depreciation and amortization ( 296,301 ) ( 247,423 ) Total $ 107,298 $ 102,671

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2024
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes	The provision for income taxes consists of the following: Year Ended December 31, 2024 2023 2022 (In thousands) Current: Federal $ 48,337 $ 49,028 $ 52,865 State and local 9,695 4,047 20,716 Foreign 32,211 27,385 21,030 Total current provision 90,243 80,460 94,611 Deferred: Federal ( 2,884 ) ( 2,823 ) ( 5,830 ) State and local ( 573 ) ( 754 ) ( 1,350 ) Foreign ( 421 ) ( 2,238 ) 633 Total deferred provision ( 3,878 ) ( 5,815 ) ( 6,547 ) Provision for income taxes $ 86,365 $ 74,645 $ 88,064
Difference between the U.S. federal statutory tax rate and the Company's effective tax rate	The difference between the U.S. federal statutory tax rate of 21.0 % and the Company’s effective tax rate is as follows: Year Ended December 31, 2024 2023 2022 U.S. federal statutory tax rate 21.0 % 21.0 % 21.0 % State and local taxes, net of federal benefit 1.9 0.8 4.6 Tax credits ( 1.3 ) ( 1.0 ) ( 0.4 ) Foreign rate differential detriment (benefit) 1.4 0.9 ( 0.1 ) Excess tax detriment (benefit) from stock-based compensation 0.4 0.1 ( 0.1 ) Other, net 0.6 0.6 1.0 Effective tax rate 24.0 % 22.4 % 26.0 %
Summary of Company's Net Deferred Tax Assets	The following is a summary of the Company’s net deferred tax assets: As of December 31, 2024 2023 (In thousands) Deferred tax assets: Stock compensation expense $ 4,880 $ 4,441 Operating lease liabilities 15,753 17,128 Deferred compensation 2,700 2,596 Capitalized software development 3,130 791 Other 1,096 224 Total deferred tax assets 27,559 25,180 Valuation allowance — — Net deferred tax assets 27,559 25,180 Deferred tax liabilities: Depreciation ( 6,990 ) ( 8,617 ) Goodwill and intangible assets ( 5,307 ) ( 3,987 ) Operating lease right-of-use assets ( 12,515 ) ( 13,507 ) Other deferred tax liabilities — ( 276 ) Deferred tax asset (liability), net $ 2,747 $ ( 1,207 )
Reconciliation of the Unrecognized Tax Benefits	A reconciliation of the Company’s unrecognized tax benefits is as follows: Year Ended December 31, 2024 2023 2022 (In thousands) Balance at beginning of year $ 3,130 $ 9,835 $ 15,089 Increase/(decrease) based on tax positions related to prior periods — — 160 (Decrease) related to settlements with taxing authorities ( 3,130 ) ( 6,705 ) ( 5,414 ) Balance at end of year $ — $ 3,130 $ 9,835

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Summary of the Change in the Company's Outstanding Shares of Common Stock	The following is a summary of the changes in the Company’s outstanding shares of voting common stock: Year Ended December 31, 2024 2023 2022 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,900 37,648 37,919 Exercise of stock options 16 6 29 Issuance of restricted stock and performance shares, net of cancellations 125 97 66 Shares withheld for withholding tax payments ( 61 ) ( 81 ) ( 86 ) Repurchases ( 342 ) — ( 280 ) Reissuance of treasury stock 8 5 — Treasury stock used for acquisition — 225 — Outstanding shares of voting common stock at the end of year 37,646 37,900 37,648

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation Expense	Total stock-based compensation expense was as follows: Year Ended December 31, 2024 2023 2022 (In thousands) Employees Full Value Awards $ 27,607 $ 24,205 $ 24,593 Stock options 1,728 3,592 3,583 29,335 27,797 28,176 Non-employee directors Restricted stock and restricted stock units 1,512 1,393 1,688 Total stock-based compensation $ 30,847 $ 29,190 $ 29,864
Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted	The following table represents the assumptions used for the Black-Scholes option-pricing model to determine the per share weighted-average fair value for options granted: Year Ended December 31, 2024 2023 2022 Expected life (years) 4.7 5.0 5.0 Risk-free interest rate 4.0 % 3.6 % 1.5 % Expected volatility 39.2 % 35.8 % 32.6 % Expected dividend yield 1.3 % 0.8 % 0.7 %
Stock Option Activity	The following table reports stock option activity during the years ended December 31, 2024, 2023 and 2022 and the intrinsic value as of December 31, 2024: Number Weighted-Average Exercise Price ($) Remaining Intrinsic Value ($) (In thousands) Outstanding at December 31, 2021 312,753 274.35 Granted 23,904 352.15 Canceled or forfeited ( 1,646 ) 421.08 Exercised ( 28,758 ) 157.08 Outstanding at December 31, 2022 306,253 290.65 Granted 13,908 358.53 Canceled or forfeited ( 551 ) 382.12 Exercised ( 5,653 ) 166.34 Outstanding at December 31, 2023 313,957 295.74 Granted 20,793 220.50 Canceled or forfeited ( 229,478 ) 276.79 Exercised ( 22,044 ) 205.28 1,314 Outstanding at December 31, 2024 83,228 353.14 3.2 115 Exercisable at December 31, 2024 46,710 411.47 2.1 —
Schedule of Estimate, Target and Maximum Performance Share Payouts	The following table reports the Company’s performance payout estimates for three-year performance period awards as of December 31, 2024, as well as the target and maximum share payouts for each award date granted: Award Date Estimate Target Maximum January 31, 2022 7,771 17,844 35,688 March 1, 2022 1,736 3,986 7,972 February 15, 2023 11,060 17,607 35,214 February 15, 2024 31,681 30,811 61,622 June 3, 2024 1,797 1,797 3,594
Full Value Awards activity	The following table reports Full Value Awards activity during the years ended December 31, 2024, 2023 and 2022: Number of Restricted Shares Weighted-Average Grant Date Fair Value Outstanding at December 31, 2021 162,610 $ 316.56 Granted 72,861 Performance share pay-out — Canceled ( 8,513 ) Vested ( 64,602 ) Outstanding at December 31, 2022 162,356 $ 321.04 Granted 90,242 Performance share pay-out 12,145 Canceled ( 5,272 ) Vested ( 98,927 ) Outstanding at December 31, 2023 160,544 $ 346.15 Granted 150,031 Performance share pay-out 4,739 Canceled ( 29,581 ) Vested ( 85,932 ) Outstanding at December 31, 2024 199,801 $ 276.74

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2024
Earnings Per Share [Abstract]
Basic and Diluted Weighted Average Shares Outstanding Used to Compute Earnings Per Share	The following table sets forth basic and diluted weighted average shares outstanding used to compute earnings per share: Year Ended December 31, 2024 2023 2022 (In thousands, except per share amounts) Basic weighted average shares outstanding 37,600 37,546 37,468 Dilutive effect of stock options and full value awards 72 108 175 Diluted weighted average shares outstanding 37,672 37,654 37,643 Basic earnings per share $ 7.29 $ 6.87 $ 6.68 Diluted earnings per share 7.28 6.85 6.65

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2024
Leases [Abstract]
Schedule of Components of Operating Lease Expense	The following table presents the components of operating lease expense for the years ended December 31, 2024, 2023 and 2022: Year Ended December 31, Lease cost: Classification 2024 2023 2022 (In thousands) Operating lease cost - office space Occupancy $ 11,034 $ 12,861 $ 13,015 Operating lease cost for subleased/assigned properties Other, net — — 469 Operating lease cost - equipment Technology and communications 390 98 — Variable lease costs Occupancy 3,327 237 96 Sublease income Other, net — — ( 405 ) Total operating lease cost $ 14,751 $ 13,196 $ 13,175
Summary of Weighted Average Remaining Lease Term and Discount Rate	The weighted average remaining lease term and weighted average discount rate are as follows: As of Lease Term and Discount Rate December 31, 2024 December 31, 2023 Weighted average remaining lease term (in years) - operating leases 8.8 9.6 Weighted average discount rate - operating leases 6.1 % 6.0 % Weighted average remaining lease term (in years) - finance leases 0.8 1.8 Weighted average discount rate - finance leases 7.2 % 7.2 %
Schedule of Maturity of Lease Liabilities	The following table presents the maturity of lease liabilities as of December 31, 2024: Operating Leases Finance Leases (In thousands) 2025 $ 12,699 88 2026 12,115 — 2027 9,286 — 2028 8,675 — 2029 8,992 — 2030 and thereafter 42,186 — Total lease payments 93,953 88 Less: imputed interest 21,299 3 Present value of lease liabilities $ 72,654 $ 85

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2024
Segment Reporting [Abstract]
Summary of Revenue and Long-lived Assets	Revenues for the years ended December 31, 2024, 2023 and 2022 and long-lived assets as of December 31, 2024 and 2023 were as follows: Year Ended December 31, 2024 2023 2022 (In thousands) Revenues United States $ 568,595 $ 523,683 $ 510,802 United Kingdom 161,838 147,019 126,862 Other 86,664 81,845 80,636 Total $ 817,097 $ 752,547 $ 718,300 As of December 31, 2024 December 31, 2023 (In thousands) Long-lived assets, as defined United States $ 92,983 $ 87,502 United Kingdom 12,683 14,713 Other 1,632 456 Total $ 107,298 $ 102,671

Cash and Cash Equivalents and_2

Cash and Cash Equivalents and Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2024
Cash and Cash Equivalents [Abstract]
Summary of Reconciliation of Cash and Cash Equivalents with Restricted or Segregated Cash	The following table provides a reconciliation of cash and cash equivalents together with restricted or segregated cash as reported within the Consolidated Statements of Financial Condition to the sum of the same such amounts shown in the Consolidated Statements of Cash Flows: As of December 31, Statement of Financial Condition Location 2024 2023 2022 (In thousands) Cash and cash equivalents Cash and cash equivalents $ 544,478 $ 451,280 $ 430,746 Cash segregated for regulatory Cash segregated under federal 47,107 45,122 50,947 Restricted cash deposits with clearing Receivables from broker-dealers, 107,652 115,151 88,923 Other cash deposits Prepaid expenses and other assets 1,222 119 2,048 Total $ 700,459 $ 611,672 $ 572,664

Parent Company Information (Tab

Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2024
Condensed Financial Information Disclosure [Abstract]
Condensed Statements of Financial Condition	The following tables present Parent Company-only financial information that should be read in conjunction with the consolidated financial statements of the Company. MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Financial Condition As of December 31, 2024 December 31, 2023 (In thousands) ASSETS Cash and cash equivalents $ 94,332 $ 65,951 Investments, at fair value 60,735 30,225 Accounts receivable 1,397 1,923 Receivable from subsidiaries 22,606 18,010 Intangible assets, net of accumulated amortization 18 21 Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization 15,617 17,644 Operating lease right-of-use assets 51,416 55,113 Investments in subsidiaries 1,179,524 1,140,798 Prepaid expenses and other assets 40,903 45,140 Income and other tax receivable 8,253 7,674 Total assets $ 1,474,801 $ 1,382,499 LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities Accrued employee compensation 9,707 $ 8,589 Income and other tax liabilities 722 3,000 Accounts payable, accrued expenses and other liabilities 10,646 8,212 Operating lease liabilities 65,066 69,735 Total liabilities 86,141 89,536 Stockholders’ equity Preferred stock — — Series A Preferred Stock — — Common stock voting 123 123 Common stock non-voting — — Additional paid-in capital 350,701 333,292 Treasury stock ( 333,369 ) ( 260,298 ) Retained earnings 1,405,904 1,244,216 Accumulated other comprehensive loss ( 34,699 ) ( 24,370 ) Total stockholders’ equity 1,388,660 1,292,963 Total liabilities and stockholders’ equity $ 1,474,801 $ 1,382,499 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations Year Ended December 31, 2024 2023 2022 (In thousands) Revenues $ 246,600 $ 270,700 $ 257,200 Expenses Employee compensation and benefits 12,091 13,938 17,655 Depreciation and amortization 2,186 2,153 2,136 Professional and consulting fees 6,149 5,828 5,528 General and administrative 1,660 2,301 3,081 Total expenses 22,086 24,220 28,400 Operating income 224,514 246,480 228,800 Other income (expense) Interest income 4,615 3,557 272 Interest expense ( 167 ) ( 155 ) ( 271 ) Equity in earnings of unconsolidated affiliate 1,395 735 1,126 Other, net ( 5,088 ) ( 369 ) ( 2,633 ) Total other income (expense) 755 3,768 ( 1,506 ) Income before income taxes and equity in undistributed earnings of subsidiaries 225,269 250,248 227,294 Benefit from income taxes ( 6,550 ) ( 5,586 ) ( 7,710 ) Income before equity in undistributed income of subsidiaries 231,819 255,834 235,004 Equity in undistributed income of subsidiaries 42,362 2,221 15,220 Net income 274,181 258,055 250,224 Other comprehensive income (loss), net ( 10,329 ) 13,327 ( 24,367 ) Comprehensive income $ 263,852 $ 271,382 $ 225,857 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2024 2023 2022 (In thousands) Cash flows from operating activities Net income $ 274,181 $ 258,055 $ 250,224 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 2,186 2,153 2,136 Amortization of operating lease right-of-use assets 3,697 3,361 3,347 Stock-based compensation expense 7,130 9,725 12,554 Deferred taxes 397 101 ( 5,076 ) Equity in undistributed income of subsidiaries ( 42,362 ) ( 2,221 ) ( 15,220 ) Other 4,304 ( 4,675 ) 441 Changes in operating assets and liabilities: (Increase)/decrease in accounts receivable 526 ( 1,154 ) ( 769 ) Decrease in receivable from subsidiaries 12,694 5,474 7,931 Decrease/(increase) in prepaid expenses and other assets 304 1,296 ( 1,175 ) (Increase)/decrease in mutual funds held in rabbi trust ( 94 ) ( 189 ) 984 (Decrease)/increase in accrued employee compensation 1,118 ( 1,104 ) ( 1,372 ) (Increase)/decrease in income and other tax receivables ( 579 ) 3,800 ( 9,711 ) Increase/(decrease) increase in income and other tax liabilities ( 2,278 ) 2,287 62 (Decrease)/increase in accounts payable, accrued expenses and other liabilities 4,809 ( 861 ) 443 (Decrease) in operating lease liabilities ( 4,669 ) ( 3,624 ) ( 3,689 ) Net cash provided by operating activities 261,364 272,424 241,110 Cash flows from investing activities Acquisition of business — ( 81,161 ) — Acquisition of equity method investment — — ( 34,400 ) Investments in subsidiaries ( 30 ) ( 10,058 ) ( 8,326 ) Available-for-sale investments Proceeds from maturities and sales 12,440 4,454 — Purchases ( 42,810 ) ( 28,818 ) — Purchases of furniture, equipment and leasehold improvements ( 156 ) ( 239 ) ( 96 ) Net cash (used in) investing activities ( 30,556 ) ( 115,822 ) ( 42,822 ) Cash flows from financing activities Cash dividend on common stock ( 112,697 ) ( 109,658 ) ( 105,942 ) Exercise of stock options 2,988 940 672 Withholding tax payments on Full Value Awards vesting and stock option exercises ( 16,194 ) ( 25,839 ) ( 23,404 ) Repurchases of common stock ( 75,474 ) — ( 87,540 ) Proceeds from short-term borrowings 100,000 100,000 100,000 Repayments of short-term borrowings ( 100,000 ) ( 100,000 ) ( 100,000 ) Net cash (used in) financing activities ( 201,377 ) ( 134,557 ) ( 216,214 ) Effect of exchange rate changes on cash and cash equivalents — ( 3 ) 15 Cash and cash equivalents including restricted cash Net increase (decrease) for the period 29,431 22,042 ( 17,911 ) Beginning of period 65,951 43,909 61,820 End of period $ 95,382 $ 65,951 $ 43,909 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows (Continued) Year Ended December 31, 2024 2023 2022 (In thousands) Supplemental cash flow information: Cash paid for income taxes $ 53,999 $ 55,784 $ 65,764 Cash paid for interest 167 35 271 Non-cash investing and financing activity: Exercise of stock options - cashless $ 1,735 $ — $ 3,845 Right-of-use assets obtained in exchange for operating lease liabilities — 1,072 — Treasury stock used for acquisition of business — 43,841 —
Condensed Statements of Operations	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations Year Ended December 31, 2024 2023 2022 (In thousands) Revenues $ 246,600 $ 270,700 $ 257,200 Expenses Employee compensation and benefits 12,091 13,938 17,655 Depreciation and amortization 2,186 2,153 2,136 Professional and consulting fees 6,149 5,828 5,528 General and administrative 1,660 2,301 3,081 Total expenses 22,086 24,220 28,400 Operating income 224,514 246,480 228,800 Other income (expense) Interest income 4,615 3,557 272 Interest expense ( 167 ) ( 155 ) ( 271 ) Equity in earnings of unconsolidated affiliate 1,395 735 1,126 Other, net ( 5,088 ) ( 369 ) ( 2,633 ) Total other income (expense) 755 3,768 ( 1,506 ) Income before income taxes and equity in undistributed earnings of subsidiaries 225,269 250,248 227,294 Benefit from income taxes ( 6,550 ) ( 5,586 ) ( 7,710 ) Income before equity in undistributed income of subsidiaries 231,819 255,834 235,004 Equity in undistributed income of subsidiaries 42,362 2,221 15,220 Net income 274,181 258,055 250,224 Other comprehensive income (loss), net ( 10,329 ) 13,327 ( 24,367 ) Comprehensive income $ 263,852 $ 271,382 $ 225,857
Condensed Statements of Cash Flows	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2024 2023 2022 (In thousands) Cash flows from operating activities Net income $ 274,181 $ 258,055 $ 250,224 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 2,186 2,153 2,136 Amortization of operating lease right-of-use assets 3,697 3,361 3,347 Stock-based compensation expense 7,130 9,725 12,554 Deferred taxes 397 101 ( 5,076 ) Equity in undistributed income of subsidiaries ( 42,362 ) ( 2,221 ) ( 15,220 ) Other 4,304 ( 4,675 ) 441 Changes in operating assets and liabilities: (Increase)/decrease in accounts receivable 526 ( 1,154 ) ( 769 ) Decrease in receivable from subsidiaries 12,694 5,474 7,931 Decrease/(increase) in prepaid expenses and other assets 304 1,296 ( 1,175 ) (Increase)/decrease in mutual funds held in rabbi trust ( 94 ) ( 189 ) 984 (Decrease)/increase in accrued employee compensation 1,118 ( 1,104 ) ( 1,372 ) (Increase)/decrease in income and other tax receivables ( 579 ) 3,800 ( 9,711 ) Increase/(decrease) increase in income and other tax liabilities ( 2,278 ) 2,287 62 (Decrease)/increase in accounts payable, accrued expenses and other liabilities 4,809 ( 861 ) 443 (Decrease) in operating lease liabilities ( 4,669 ) ( 3,624 ) ( 3,689 ) Net cash provided by operating activities 261,364 272,424 241,110 Cash flows from investing activities Acquisition of business — ( 81,161 ) — Acquisition of equity method investment — — ( 34,400 ) Investments in subsidiaries ( 30 ) ( 10,058 ) ( 8,326 ) Available-for-sale investments Proceeds from maturities and sales 12,440 4,454 — Purchases ( 42,810 ) ( 28,818 ) — Purchases of furniture, equipment and leasehold improvements ( 156 ) ( 239 ) ( 96 ) Net cash (used in) investing activities ( 30,556 ) ( 115,822 ) ( 42,822 ) Cash flows from financing activities Cash dividend on common stock ( 112,697 ) ( 109,658 ) ( 105,942 ) Exercise of stock options 2,988 940 672 Withholding tax payments on Full Value Awards vesting and stock option exercises ( 16,194 ) ( 25,839 ) ( 23,404 ) Repurchases of common stock ( 75,474 ) — ( 87,540 ) Proceeds from short-term borrowings 100,000 100,000 100,000 Repayments of short-term borrowings ( 100,000 ) ( 100,000 ) ( 100,000 ) Net cash (used in) financing activities ( 201,377 ) ( 134,557 ) ( 216,214 ) Effect of exchange rate changes on cash and cash equivalents — ( 3 ) 15 Cash and cash equivalents including restricted cash Net increase (decrease) for the period 29,431 22,042 ( 17,911 ) Beginning of period 65,951 43,909 61,820 End of period $ 95,382 $ 65,951 $ 43,909 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows (Continued) Year Ended December 31, 2024 2023 2022 (In thousands) Supplemental cash flow information: Cash paid for income taxes $ 53,999 $ 55,784 $ 65,764 Cash paid for interest 167 35 271 Non-cash investing and financing activity: Exercise of stock options - cashless $ 1,735 $ — $ 3,845 Right-of-use assets obtained in exchange for operating lease liabilities — 1,072 — Treasury stock used for acquisition of business — 43,841 —

Organization and Principal Bu_2

Organization and Principal Business Activity - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2024 Institutional_Investor_and_BrokerDealer_Firm
Accounting Policies [Line Items]
Date of incorporation	Apr. 11, 2000
Minimum [Member]
Accounting Policies [Line Items]
Number of institutional investor and broker-dealer firms	2,100

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) Revenue	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Significant Accounting Policies [Line Items]
Allowance for credit losses	$ 982	$ 577
Provision for bad debts	800	400	$ 600
Write-offs and other charges against the allowance for credit losses	$ 400	$ 300	$ 100
Number of revenue streams | Revenue	4
Maximum [Member]
Significant Accounting Policies [Line Items]
Contractual maturities accounts receivable	1 year
Estimated useful life of fixed assets	7 years
Hosting service contract, amortization period	5 years
Maximum [Member] | Business Combinations [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	15 years
Maximum [Member] | Internally Developed Software [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	5 years
Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of fixed assets	3 years
Hosting service contract, amortization period	1 year
Minimum [Member] | Business Combinations [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	1 year
Minimum [Member] | Internally Developed Software [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	3 years

Significant Accounting Polici_5

Significant Accounting Policies - Summary of Commission Revenue by Fee Type (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Commission revenue by fee type
Revenues	$ 817,097	$ 752,547	$ 718,300
Commissions [Member]
Commission revenue by fee type
Disclosed trading	361,252	323,038	321,603
Open Trading - matched principal trading	177,966	178,517	175,440
Other Variable Transaction	20,016	4,979	0
Total variable transaction fees	578,544	521,756	514,021
Distribution fees and unused minimum fees	133,166	141,208	127,162
Revenues	711,710	662,964	641,183
Commissions [Member] | US Government Bonds [Member]
Commission revenue by fee type
Open Trading - matched principal trading	$ 19,310	$ 15,222	$ 16,978

Significant Accounting Polici_6

Significant Accounting Policies - Summary of Information Services Revenue by Timing of Recognition (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Significant Accounting Policies [Line Items]
Revenues	$ 817,097	$ 752,547	$ 718,300
Information Services [Member]
Significant Accounting Policies [Line Items]
Revenues	50,540	46,383	39,314
Information Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	49,560	45,102	38,452
Information Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 980	$ 1,281	$ 862

Significant Accounting Polici_7

Significant Accounting Policies - Summary of Post-Trade Services Revenue by Timing of Recognition (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Significant Accounting Policies [Line Items]
Revenues	$ 817,097	$ 752,547	$ 718,300
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Revenues	42,487	40,178	36,877
Post-trade Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	42,170	40,061	36,835
Post-trade Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 317	$ 117	$ 42

Significant Accounting Polici_8

Significant Accounting Policies - Summary of Technology Services Revenue by Timing of Recognition (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Significant Accounting Policies [Line Items]
Revenues	$ 817,097	$ 752,547	$ 718,300
Technology Services [Member]
Significant Accounting Policies [Line Items]
Revenues	12,360	3,022	926
Technology Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	12,334	3,021	926
Technology Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 26	$ 1	$ 0

Significant Accounting Polici_9

Significant Accounting Policies - Summary of Revenue Recognized from Contract Liabilities and Remaining Balance (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	$ 4,539
Payments received in advance of services to be performed	43,597
Revenue recognized for services performed during the period	(43,120)
Foreign Currency Translation	(13)
Deferred revenues, ending balance	5,003
Information Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	3,049
Payments received in advance of services to be performed	14,948
Revenue recognized for services performed during the period	(14,695)
Deferred revenues, ending balance	3,302
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	923
Payments received in advance of services to be performed	20,436
Revenue recognized for services performed during the period	(20,060)
Foreign Currency Translation	(13)
Deferred revenues, ending balance	1,286
Technology Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	567
Payments received in advance of services to be performed	8,213
Revenue recognized for services performed during the period	(8,365)
Deferred revenues, ending balance	$ 415

Significant Accounting Polic_10

Significant Accounting Policies - Additional Information (Detail 1) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2025-01-01 $ in Millions	Dec. 31, 2024 USD ($)
Significant Accounting Policies [Line Items]
Aggregate amount of transaction price allocated to remaining performance obligations	$ 47
Expected time to recognize revenue for remaining performance obligation	46 months

Regulatory Capital Requiremen_2

Regulatory Capital Requirements - Additional Information (Detail) $ in Millions	Dec. 31, 2024 USD ($)
U.S. Subsidiaries
Brokers And Dealers [Line Items]
Aggregate net capital and financial resources in excess of required level	$ 574.6
Aggregate net capital and financial resources, minimum capital requirement	33.8
U.S. Broker-Dealer Subsidiaries
Brokers And Dealers [Line Items]
Aggregate net capital and financial resources in excess of required level	2.3
Aggregate net capital and financial resources, minimum capital requirement	318.9
Securities reserve deposit	$ 47.1

Fair Value Measurements - Valua

Fair Value Measurements - Valuation of Company's Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Assets
Money market funds	$ 55,473	$ 18,634
Assets Fair Value Total	220,733	155,396
Liabilities
Total liabilities	936
Mutual Funds Held In Rabbi Trust [Member]
Assets
Mutual funds held in rabbi trust	11,107	10,485
U.S. Treasuries [Member]
Assets
Trading securities, Fair value	99,045	99,682
Foreign Currency Forward Position [Member]
Assets
Foreign currency forward position		1,901
Liabilities
Foreign currency forward position	936
Corporate Debt [Member]
Assets
Securities available-for-sale	55,108	24,694
Level 1 [Member]
Assets
Money market funds	55,473	18,634
Assets Fair Value Total	55,473	18,634
Level 2 [Member]
Assets
Assets Fair Value Total	165,260	136,762
Liabilities
Total liabilities	936
Level 2 [Member] | Mutual Funds Held In Rabbi Trust [Member]
Assets
Mutual funds held in rabbi trust	11,107	10,485
Level 2 [Member] | U.S. Treasuries [Member]
Assets
Trading securities, Fair value	99,045	99,682
Level 2 [Member] | Foreign Currency Forward Position [Member]
Assets
Foreign currency forward position		1,901
Liabilities
Foreign currency forward position	936
Level 2 [Member] | Corporate Debt [Member]
Assets
Securities available-for-sale	$ 55,108	$ 24,694

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Value of Financial Asset and Liability Not Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Financial assets not measured at fair value:
Financial assets not measured at fair value	$ 220,733	$ 155,396
Level 1 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	55,473	18,634
Level 2 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	165,260	136,762
Financial Assets and Liabilities not Measured [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	985,685	1,255,543
Financial Assets and Liabilities not Measured [Member] | Payables to Broker-Dealers, Clearing Organizations and Customers [Member]
Financial liabilities not measured at fair value:
Financial liabilities not measured at fair value	218,845	537,398
Financial Assets and Liabilities not Measured [Member] | Cash [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	489,005	432,646
Financial Assets and Liabilities not Measured [Member] | Cash Segregated under Federal Regulations [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	47,107	45,122
Financial Assets and Liabilities not Measured [Member] | Accounts Receivable, Net of Allowance [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	91,845	89,839
Financial Assets and Liabilities not Measured [Member] | Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	357,728	687,936
Financial Assets and Liabilities not Measured [Member] | Level 1 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	643,764	592,919
Financial Assets and Liabilities not Measured [Member] | Level 1 [Member] | Cash [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	489,005	432,646
Financial Assets and Liabilities not Measured [Member] | Level 1 [Member] | Cash Segregated under Federal Regulations [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	47,107	45,122
Financial Assets and Liabilities not Measured [Member] | Level 1 [Member] | Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	107,652	115,151
Financial Assets and Liabilities not Measured [Member] | Level 2 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	341,921	662,624
Financial Assets and Liabilities not Measured [Member] | Level 2 [Member] | Payables to Broker-Dealers, Clearing Organizations and Customers [Member]
Financial liabilities not measured at fair value:
Financial liabilities not measured at fair value	218,845	537,398
Financial Assets and Liabilities not Measured [Member] | Level 2 [Member] | Accounts Receivable, Net of Allowance [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	91,845	89,839
Financial Assets and Liabilities not Measured [Member] | Level 2 [Member] | Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	250,076	572,785
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	985,685	1,255,543
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member] | Payables to Broker-Dealers, Clearing Organizations and Customers [Member]
Financial liabilities not measured at fair value:
Financial liabilities not measured at fair value	218,845	537,398
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member] | Cash [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	489,005	432,646
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member] | Cash Segregated under Federal Regulations [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	47,107	45,122
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member] | Accounts Receivable, Net of Allowance [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	91,845	89,839
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member] | Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	357,728	687,936
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	985,685	1,255,543
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member] | Payables to Broker-Dealers, Clearing Organizations and Customers [Member]
Financial liabilities not measured at fair value:
Financial liabilities not measured at fair value	218,845	537,398
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member] | Cash [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	489,005	432,646
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member] | Cash Segregated under Federal Regulations [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	47,107	45,122
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member] | Accounts Receivable, Net of Allowance [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	91,845	89,839
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member] | Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	$ 357,728	$ 687,936

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers between Level 1, Level 2 and Level 3 securities	$ 0	$ 0
Cash collateral deposit	1,100,000
Proceeds from the sales and maturities of securities available-for-sale	62,400,000	29,500,000
Purchases of investments	93,400,000	78,600,000
Credit losses on available-for-sale securities	$ 0	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Foreign Currency Forward Contracts (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Derivatives Fair Value [Line Items]
Notional value	$ 64,454	$ 61,858
Fair value of notional	63,518	63,759
Fair value of the (liability)/asset	$ (936)	$ 1,901

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Realized and Unrealized Gains and Losses on Foreign Currency Forward Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Gain (Loss) on Securities [Line Items]
Unrealized gain/(loss)	$ 19	$ 1,719	$ (2,625)
Realized gain/(loss)	(324)	(149)	0
Forward Contracts [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gain/(loss)	(2,838)	3,590	(1,688)
Realized gain/(loss)	1,148	(1,470)	802
Total gain/(loss)	$ (1,690)	$ 2,120	$ (886)

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Company's Investments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Investments, Amortized cost	$ 166,143	$ 134,903
Investments, Gross unrealized gains	1,074	673
Investments, Gross unrealized losses	(1,957)	(715)
Investments, at fair value	165,260	134,861
Corporate Debt [Member]
Schedule Of Available For Sale Securities [Line Items]
Securities available-for-sale, Amortized Cost	55,447	24,705
Securities available-for-sale, Gross unrealized gains	88	55
Securities available-for-sale, Gross unrealized losses	(427)	(66)
Securities available-for-sale, Fair value	55,108	24,694
U.S. Treasuries [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	100,484	99,236
Trading securities, Gross unrealized gains	86	446
Trading securities, Gross unrealized losses	(1,525)
Trading securities, Fair value	99,045	99,682
Mutual Funds Held In Rabbi Trust [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	10,212	10,962
Trading securities, Gross unrealized gains	900	172
Trading securities, Gross unrealized losses	(5)	(649)
Trading securities, Fair value	$ 11,107	$ 10,485

Fair Value Measurements - Sum_4

Fair Value Measurements - Summary of Companies unrealized and realized gains and losses on investments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	$ 19	$ 1,719	$ (2,625)
Realized gains/(losses)	(324)	(149)	0
Securities sold, not yet purchased gross realized gains	174	0	0
Corporate Debt [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	(328)	(11)	0
Realized gains/(losses)	4	(11)	0
U.S. Treasuries [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	(1,025)	446	(534)
Mutual Funds Held In Rabbi Trust [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	1,372	1,284	(2,091)
Realized gains/(losses)	$ (328)	$ (138)	$ 0

Fair Value Measurements - Sum_5

Fair Value Measurements - Summary of Fair Value of Investments Based upon Contractual Maturities (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Less than one year	$ 59,324	$ 60,483
Due in 1 - 5 years	94,829	63,893
Total	154,153	124,376
U.S. Treasuries [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than one year	49,978	49,756
Due in 1 - 5 years	49,067	49,926
Total	99,045	99,682
Corporate Debt [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than one year	9,346	10,727
Due in 1 - 5 years	45,762	13,967
Total	$ 55,108	$ 24,694

Fair Value Measurements - Sum_6

Fair Value Measurements - Summary of Fair Values and Unrealized Losses on Investments (Detail) - Corporate Debt [Member] - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than Twelve Months, Estimated Fair value	$ 38,041	$ 17,658
Less than Twelve Months, Gross unrealized losses	(426)	(66)
Twelve Months or More, Gross unrealized losses	1,226	0
Twelve Months or More, Gross unrealized losses	(1)	0
Estimated Fair value, Total	39,267	17,658
Gross unrealized losses, Total	$ (427)	$ (66)

Receivables from and Payables_3

Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers - Schedule of Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Receivables from broker-dealers, clearing organizations and customers:
Securities failed-to-deliver - broker-dealers and clearing organizations	$ 109,307	$ 282,125
Securities failed-to-deliver - customers	136,424	284,322
Cash deposits with clearing organizations and broker-dealers	107,652	115,151
Other	4,345	6,338
Total	357,728	687,936
Payables to broker-dealers, clearing organizations and customers:
Securities failed-to-receive - broker-dealers and clearing organizations	158,694	125,022
Securities failed-to-receive - customers	51,916	405,186
Other	8,235	7,190
Total	$ 218,845	$ 537,398

Acquisitions and Equity Inves_3

Acquisitions and Equity Investments - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	Apr. 19, 2024	Oct. 02, 2023	Dec. 31, 2024	Dec. 31, 2023	May 01, 2022
Business Acquisition [Line Items]
Goodwill			$ 236,706	$ 236,706
Pragma [Member]
Business Acquisition [Line Items]
Aggregate purchase price		$ 125,002
Cash consideration		81,200
Amortizable intangible assets		38,900
Goodwill		$ 81,917
Business combination, shares of common stock		224,776
Business acquisition value of common stock transferrable		$ 43,800
Business combination, period for shares of common stock placed in escrow		12 months
Business combination, shares of common stock received period		6 months
Pragma [Member] | Escrow [Member]
Business Acquisition [Line Items]
Business combination, shares of common stock		8,603
RFQ Hub Holdings LLC [Member]
Business Acquisition [Line Items]
Recorded investments					$ 34,400
Proportionate share in net earnings			1,400	700
Company received distribution			3,200
Reimbursable support costs for equity method investee			2,100	$ 1,100
Receivable from the equity method investee			600
Cash consideration	$ 37,900
Additional interest acquired	49%
RFQ Hub Holdings LLC [Member] | Other Investees [Member]
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage	92%
RFQ Hub Holdings LLC [Member] | Prepaid Expenses And Other Assets [Member]
Business Acquisition [Line Items]
Recorded investments			$ 34,400

Acquisitions and Equity Inves_4

Acquisitions and Equity Investments - Summary of Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Oct. 02, 2023	Dec. 31, 2024	Dec. 31, 2023
Business Acquisition [Line Items]
Goodwill		$ 236,706	$ 236,706
Pragma [Member]
Business Acquisition [Line Items]
Purchase price	$ 125,002
Less: acquired cash	(2,685)
Purchase price, net of acquired cash	122,317
Intangible assets	(38,900)
Accounts receivable	(2,637)
Prepaid expenses and other assets	(4,181)
Accounts payable, accrued expenses and other liabilities	5,318
Goodwill	$ 81,917

Acquisitions and Equity Inves_5

Acquisitions and Equity Investments - Summary of Fair Value of Acquired Intangible Assets (Detail) - Pragma [Member] $ in Thousands	Oct. 02, 2023 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Costs	$ 38,900
Developed technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Costs	$ 28,500
Useful lives	7 years
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Costs	$ 9,200
Useful lives	15 years
Tradename - Finite Life [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Costs	$ 1,200
Useful lives	15 years

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Amortization expense associated with identifiable intangible assets	$ 19.8	$ 18.6	$ 16.4
Estimated total amortization expense 2025	16.8
Estimated total amortization expense 2026	15.1
Estimated total amortization expense 2027	13.7
Estimated total amortization expense 2028	12.2
Estimated total amortization expense 2029	11.2
Indefinite-lived Intangible Assets [Member]
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 236.7	$ 236.7

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Company's Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Finite Lived Intangible Assets [Line Items]
Cost	$ 179,219	$ 181,478
Accumulated amortization	(81,141)	(62,370)
Net carrying amount	98,078	119,108
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Cost	138,089	140,348
Accumulated amortization	(64,698)	(50,987)
Net carrying amount	73,391	89,361
Technology and Other Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Cost	41,130	41,130
Accumulated amortization	(16,443)	(11,383)
Net carrying amount	$ 24,687	$ 29,747

Capitalized Software, Furnitu_3

Capitalized Software, Furniture, Equipment and Leasehold Improvements - Capitalized Software Development Costs, Furniture, Equipment and Leasehold Improvements, Net of Accumulated Depreciation and Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 403,599	$ 350,094
Accumulated depreciation and amortization	(296,301)	(247,423)
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	107,298	102,671
Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	307,722	261,850
Computer Hardware and Related Software [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	50,770	42,913
Office Hardware [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	7,201	7,609
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	6,520	6,508
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 31,386	$ 31,214

Capitalized Software, Furnitu_4

Capitalized Software, Furniture, Equipment and Leasehold Improvements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Software development costs	$ 49.1	$ 43.1

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Current:
Federal	$ 48,337	$ 49,028	$ 52,865
State and local	9,695	4,047	20,716
Foreign	32,211	27,385	21,030
Total current provision	90,243	80,460	94,611
Deferred:
Federal	(2,884)	(2,823)	(5,830)
State and local	(573)	(754)	(1,350)
Foreign	(421)	(2,238)	633
Total deferred provision	(3,878)	(5,815)	(6,547)
Provision for income taxes	$ 86,365	$ 74,645	$ 88,064

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from U.S. operations	$ 235,800	$ 228,800	$ 236,400
Pre-tax income from foreign operations	$ 124,700	$ 103,900	$ 101,900
U.S. federal statutory tax rate	21%	21%	21%
Provision for income taxes	$ 86,365	$ 74,645	$ 88,064
Unrecognized tax benefits	0	3,130	9,835	$ 15,089
Recognized penalties and interest on unrecognized tax benefits	300	1,600	$ 5,800
Penalties and interest accrued on unrecognized tax benefits	$ 0	$ 2,600
New York State [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2015 2016 2017 2018 2019 2020
New York City [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2016 2017 2018

Income Taxes - Difference Betwe

Income Taxes - Difference Between the Company's Reported Provision for Income Taxes and the U.S. Federal Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
U.S. federal statutory tax rate	21%	21%	21%
State and local taxes, net of federal benefit	1.90%	0.80%	4.60%
Tax credits	(1.30%)	(1.00%)	(0.40%)
Foreign rate differential detriment (benefit)	1.40%	0.90%	(0.10%)
Excess tax detriment (benefit) from stock-based compensation	0.40%	0.10%	(0.10%)
Other, net	0.60%	0.60%	1%
Effective tax rate	24%	22.40%	26%

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Stock compensation expense	$ 4,880	$ 4,441
Operating lease liabilities	15,753	17,128
Deferred compensation	2,700	2,596
Capitalized software development	3,130	791
Other	1,096	224
Total deferred tax assets	27,559	25,180
Valuation allowance	0
Net deferred tax assets	27,559	25,180
Deferred tax liabilities:
Depreciation	(6,990)	(8,617)
Goodwill and intangible assets	(5,307)	(3,987)
Operating lease right-of-use assets	(12,515)	(13,507)
Other deferred tax liabilities	0	(276)
Deferred tax asset (liability), net	$ 2,747	$ (1,207)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 3,130	$ 9,835	$ 15,089
Increase/(decrease) based on tax positions related to prior periods	0	0	160
(Decrease) related to cash settlements with taxing authorities	(3,130)	(6,705)	(5,414)
Balance at end of year	$ 0	$ 3,130	$ 9,835

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Common stock, shares authorized	110,000,000	110,000,000		110,000,000	110,000,000
Common stock entitles				one
Cash dividends declared per common share	$ 0.74	$ 0.72	$ 0.7	$ 2.96	$ 2.88	$ 2.8
2022 Repurchase Program and 2024 Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase program, value				$ 75
Shares repurchase program, shares				341,477
Share repurchase program, remaining capacity	$ 225			$ 225
Common Stock Non-Voting [Member]
Class of Stock [Line Items]
Common stock, shares authorized	10,000,000	10,000,000		10,000,000	10,000,000
Common Stock Voting [Member]
Class of Stock [Line Items]
Common stock, shares authorized	110,000,000			110,000,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of the Companys Change in the Common Stock (Detail) - shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,899,688
Exercise of stock options	22,044	5,653	28,758
Outstanding shares of voting common stock at the end of year	37,646,374	37,899,688
Voting Common Stock [Member]
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,900,000	37,648,000	37,919,000
Exercise of stock options	16,000	6,000	29,000
Issuance of restricted stock and performance shares, net of cancellations	125,000	97,000	66,000
Shares withheld for withholding tax payments	(61,000)	(81,000)	(86,000)
Repurchases	(342,000)	0	(280,000)
Reissuance of treasury stock	8,000	5,000	0
Treasury stock used for acquisition	0	225,000	0
Outstanding shares of voting common stock at the end of year	37,646,000	37,900,000	37,648,000

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Jun. 30, 2024	Apr. 30, 2023	Mar. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Jun. 08, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under the stock incentive plan				2,562,436
Period vested for option grants				3 years
Options Expiration Period				6 years
Weighted-average fair value option granted				$ 77.16	$ 123.47	$ 101.38
Grant date fair value				$ 1,314
Fair value assumptions, Dividend yield rate				1.30%	0.80%	0.70%
Closing price of common stock				$ 226.04
Unrecognized compensation costs related to non-vested				$ 1,800
Weighted-average period over which cost is expected to be recognized				1 year 6 months
Stock based compensation, Description		The performance stock units vest 25% on each of the third and fourth anniversaries of the grant date and 50% on the fifth anniversary of the grant date, subject to certification of the performance criteria and his continued service through the respective vesting dates.
Grant date deemed probable to vest				$ 0
Common stock, shares issued				41,020,421	40,940,769
Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based payment arrangement, amount capitalized				$ 1,200	$ 900	$ 900
Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of non-option equity instruments granted during the period	1,797	5,039	3,986
Performance Based Share [Member] | Chief Operating Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award award vesting date			Mar. 01, 2025
Performance Based Share [Member] | Chief Financial Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award award vesting date	Jun. 03, 2027
Performance Based Share [Member] | Third and Fourth Anniversary [Member] | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting right, percent		25%
Performance Based Share [Member] | Fifth Anniversary [Member] | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting right, percent		50%
Employees Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under the stock incentive plan				108,055			121,221
Common stock, shares issued				8,511
Full Value Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested				$ 39,600
Weighted-average period over which cost is expected to be recognized				1 year 8 months 12 days
Minimum [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Pay-out ranges, Minimum				0%	0%	0%
Maximum [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Pay-out ranges, Maximum				200%	200%	200%

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 29,335	$ 27,797	$ 28,176
Employees [Member] | Full Value Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	27,607	24,205	24,593
Employees [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	1,728	3,592	3,583
Non-Employee Directors [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	30,847	29,190	29,864
Non-Employee Directors [Member] | Restricted Stock and Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 1,512	$ 1,393	$ 1,688

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted (Detail)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Expected life (years)	4 years 8 months 12 days	5 years	5 years
Risk-free interest rate	4%	3.60%	1.50%
Expected volatility	39.20%	35.80%	32.60%
Expected dividend yield	1.30%	0.80%	0.70%

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Number of Shares, Beginning balance	313,957	306,253	312,753
Number of Shares, Granted	20,793	13,908	23,904
Number of Shares, Canceled or forfeited	(229,478)	(551)	(1,646)
Number of Shares, Exercised	(22,044)	(5,653)	(28,758)
Number of Shares, Ending Balance	83,228	313,957	306,253
Number of Shares, Exercisable	46,710
Weighted Average Exercise Price, Beginning Balance	$ 295.74	$ 290.65	$ 274.35
Weighted Average Exercise Price, Granted	220.5	358.53	352.15
Weighted Average Exercise Price, Canceled or forfeited	276.79	382.12	421.08
Weighted Average Exercise Price, Exercised	205.28	166.34	157.08
Weighted Average Exercise Price, Ending Balance	353.14	$ 295.74	$ 290.65
Weighted Average Exercise Price, Exercisable	$ 411.47
Remaining Contractual Term, Outstanding at December 31, 2024	3 years 2 months 12 days
Remaining Contractual Term, Exercisable at December 31, 2024	2 years 1 month 6 days
Intrinsic Value, Exercised	$ 1,314
Intrinsic Value, Ending Balance	115
Intrinsic Value, Exercisable	$ 0

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Schedule of Estimated, Target and Maximum Share Payouts (Details)	Dec. 31, 2024 shares
January 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Jan. 31, 2022
Estimate	7,771
Target	17,844
Maximum	35,688
March 1, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Mar. 01, 2022
Estimate	1,736
Target	3,986
Maximum	7,972
February 15, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Feb. 15, 2023
Estimate	11,060
Target	17,607
Maximum	35,214
February 15, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Feb. 15, 2024
Estimate	31,681
Target	30,811
Maximum	61,622
June 3, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Jun. 03, 2024
Estimate	1,797
Target	1,797
Maximum	3,594

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Full Value Awards activity (Detail) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Shares, Beginning balance	160,544	162,356	162,610
Number of Restricted Shares, Granted	150,031	90,242	72,861
Number of Restricted Shares, Performance share pay-out	4,739	12,145	0
Number of Restricted Shares, Canceled	(29,581)	(5,272)	(8,513)
Number of Restricted Shares, Vested	(85,932)	(98,927)	(64,602)
Number of Restricted Shares, Ending balance	199,801	160,544	162,356
Weighted Average Grant Date Fair Value, Beginning balance	$ 346.15	$ 321.04	$ 316.56
Weighted Average Grant Date Fair Value, Ending balance	$ 276.74	$ 346.15	$ 321.04

Earnings Per Share - Basic and

Earnings Per Share - Basic and Diluted Weighted Average Shares Outstanding Used to Compute Earnings Per Share (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Basic weighted average shares outstanding	37,600	37,546	37,468
Dilutive effect of stock options and full value awards	72	108	175
Diluted weighted average shares outstanding	37,672	37,654	37,643
Basic earnings per share	$ 7.29	$ 6.87	$ 6.68
Diluted earnings per share	$ 7.28	$ 6.85	$ 6.65

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock Options And Full Value Awards [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options and full value awards excluded from the computation of diluted earnings per share	329,810	306,678	310,447

Credit Agreements and Short-t_2

Credit Agreements and Short-term Financing - Additional Information (Detail) - USD ($)		12 Months Ended
	Aug. 09, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Line Of Credit Facility [Line Items]
Interest expense on short-term debt		$ 1,400,000	$ 700,000	$ 400,000
Outstanding overdrafts payable		0
Collateralized Agreements [Member]
Line Of Credit Facility [Line Items]
Interest expense on borrowings		100,000	100,000	0
Maximum available borrowings to subsidiary under agreement		$ 500,000,000
Interest rate, stated percentage		1%
Outstanding borrowings under agreement		$ 0
Unused borrowing capacity, amount under agreement		$ 500,000,000
Collateralized Borrowing Agreement [Member]
Line Of Credit Facility [Line Items]
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:BaseRateMember
2021 Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Interest expense on borrowings			100,000	$ 300,000
Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Period of credit agreement	3 years
Sub-limit for swingline loans	$ 380,000,000
Interest expense on borrowings		$ 200,000	$ 100,000
Line of Credit Facility, Description		On August 9, 2023, the Company entered into a new three-year revolving credit facility (the “Credit Agreement”) provided by a syndicate of lenders and JPMorgan Chase Bank, N.A., as administrative agent
Revolving Credit Facility [Member] | Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Revolving loans and letters of credit	$ 750,000,000
Expiration period of credit agreement	Aug. 09, 2026
Period of credit agreement		364 days
Letter of credit outstanding		$ 100,000
Amount available under credit agreement		749,900,000
Additional borrowings under credit agreement		$ 375,000,000
Standby Letters of Credit [Member] | Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Sub-limit for letter of credit	$ 5,000,000

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)
Lessee Lease Description [Line Items]
Operating lease, option to extend	Certain leases contain options to extend the initial term at the Company’s discretion
Operating lease, existence of option to extend [true false]	true
Finance lease expense	$ 0.1
Minimum [Member]
Lessee Lease Description [Line Items]
Term of lease contract	1 year
Operating and finance leases for equipment	1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Term of lease contract	15 years
Operating and finance leases for equipment	5 years

Leases - Schedule of Components

Leases - Schedule of Components of Operating Lease Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Lease Cost [Line Items]
Total operating lease cost	$ 14,751	$ 13,196	$ 13,175
Other, net [Member]
Lease Cost [Line Items]
Operating lease cost for subleased/assigned properties	0	0	469
Sublease income	0	0	(405)
Occupancy [Member]
Lease Cost [Line Items]
Operating lease cost - office space	11,034	12,861	13,015
Variable lease costs	3,327	237	96
Technology and Communications [Member]
Lease Cost [Line Items]
Operating lease cost - equipment	$ 390	$ 98	$ 0

Leases - Summary of Weighted Av

Leases - Summary of Weighted Average Remaining Lease Term and Discount Rate (Details)	Dec. 31, 2024	Dec. 31, 2023
Leases [Abstract]
Weighted average remaining lease term (in years) - operating leases	8 years 9 months 18 days	9 years 7 months 6 days
Weighted average discount rate - operating leases	6.10%	6%
Weighted average remaining lease term (in years) - finance leases	9 months 18 days	1 year 9 months 18 days
Weighted average discount rate - finance leases	7.20%	7.20%

Leases - Schedule of Maturity o

Leases - Schedule of Maturity of Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Leases [Abstract]
2025	$ 12,699
2026	12,115
2027	9,286
2028	8,675
2029	8,992
2030 and thereafter	42,186
Total lease payments	93,953
Less: imputed interest	21,299
Present value of lease liabilities	72,654	$ 79,677
2025	88
2026	0
2027	0
2028	0
2029	0
2030 and thereafter	0
Total lease payments	88
Less: imputed interest	3
Present value of lease liabilities	$ 85
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Liabilities

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Settlement days of bond transaction	within one to two trading days

Segment and Geographic Inform_3

Segment and Geographic Information - Additional Information (Detail) - Segment	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues From External Customers And Long Lived Assets [Line Items]
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]	Chief Executive Officer [Member]
Number of reportable segments	1
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description	The Company’s CODM is its Chief Executive Officer. The CODM uses net income to evaluate income generated from segment assets in deciding whether to reinvest profits into the Company’s end-to-end trading solutions or into other areas, such as for acquisitions or to pay dividends. Net income is used to monitor budget versus actual results. The significant segment expenses and net income reviewed by the CODM conform to the presentation of such items in the consolidated statements of operations.
Geographic Concentration Risk [Member] | Total Revenue and Long-lived Assets [Member] | United Kingdom [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Concentration Risk, Percentage	10%	10%	10%

Segment and Geographic Inform_4

Segment and Geographic Information - Summary of Revenue and Long-lived Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 817,097	$ 752,547	$ 718,300
Long-lived assets	107,298	102,671
United States [Member]
Segment Reporting Information [Line Items]
Revenues	568,595	523,683	510,802
Long-lived assets	92,983	87,502
United Kingdom [Member]
Segment Reporting Information [Line Items]
Revenues	161,838	147,019	126,862
Long-lived assets	12,683	14,713
Other [Member]
Segment Reporting Information [Line Items]
Revenues	86,664	81,845	$ 80,636
Long-lived assets	$ 1,632	$ 456

Retirement and Deferred Compe_2

Retirement and Deferred Compensation Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Contribution to defined plans	$ 11.7	$ 7.6	$ 6.1
Non-qualified deferred cash incentive plan maximum eligibility percentage of employees	100%
Mutual fund investments and deferred compensation obligation, at fair value	$ 11.1	$ 10.5

Cash and Cash Equivalents and_3

Cash and Cash Equivalents and Restricted Cash - Summary of Reconciliation of Cash and Cash Equivalents with Restricted or Segregated Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 544,478	$ 451,280
Cash segregated under federal regulations	47,107	45,122
Total	700,459	611,672	$ 572,664
Cash and cash equivalents
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	544,478	451,280	430,746
Cash Segregated under Federal Regulations [Member]
Cash And Cash Equivalents [Line Items]
Cash segregated under federal regulations	47,107	45,122	50,947
Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Cash And Cash Equivalents [Line Items]
Restricted cash deposits with clearing organizations and broker-dealers	107,652	115,151	88,923
Prepaid Expenses and Other Assets [Member]
Cash And Cash Equivalents [Line Items]
Other cash deposits	$ 1,222	$ 119	$ 2,048

Parent Company Information - Co

Parent Company Information - Condensed Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
ASSETS
Cash and cash equivalents	$ 544,478	$ 451,280
Investments, at fair value	165,260	134,861
Accounts receivable	91,845	89,839
Intangible assets, net of accumulated amortization	98,078	119,108
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	107,298	102,671
Operating lease right-of-use assets	58,132	63,045
Prepaid expenses and other assets	82,584	84,499
Total assets	1,789,216	2,015,067
Liabilities
Accrued employee compensation	68,054	60,124
Income and other tax liabilities	3,683	7,892
Accounts payable, accrued expenses and other liabilities	37,320	37,013
Operating lease liabilities	72,654	79,677
Total liabilities	400,556	722,104
Stockholders' equity
Preferred stock	0	0
Common stock voting	123	123
Additional paid-in capital	350,701	333,292
Treasury stock	333,369	260,298
Retained earnings	1,405,904	1,244,216
Accumulated other comprehensive loss	(34,699)	(24,370)
Total stockholders' equity	1,388,660	1,292,963	$ 1,081,093	$ 1,041,309
Total liabilities and stockholders' equity	1,789,216	2,015,067
MarketAxess Holdings Inc. (Parent) [Member]
ASSETS
Cash and cash equivalents	94,332	65,951
Investments, at fair value	60,735	30,225
Accounts receivable	1,397	1,923
Receivable from subsidiaries	22,606	18,010
Intangible assets, net of accumulated amortization	18	21
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	15,617	17,644
Operating lease right-of-use assets	51,416	55,113
Investments in subsidiaries	1,179,524	1,140,798
Prepaid expenses and other assets	40,903	45,140
Income and other tax receivable	8,253	7,674
Total assets	1,474,801	1,382,499
Liabilities
Accrued employee compensation	9,707	8,589
Income and other tax liabilities	722	3,000
Accounts payable, accrued expenses and other liabilities	10,646	8,212
Operating lease liabilities	65,066	69,735
Total liabilities	86,141	89,536
Stockholders' equity
Preferred stock	0	0
Common stock voting	123	123
Additional paid-in capital	350,701	333,292
Treasury stock	(333,369)	(260,298)
Retained earnings	1,405,904	1,244,216
Accumulated other comprehensive loss	(34,699)	(24,370)
Total stockholders' equity	1,388,660	1,292,963
Total liabilities and stockholders' equity	1,474,801	1,382,499
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock	0	0
Series A Preferred Stock [Member] | MarketAxess Holdings Inc. (Parent) [Member]
Stockholders' equity
Preferred stock	$ 0	$ 0

Parent Company Information - _2

Parent Company Information - Condensed Statements of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues	$ 817,097	$ 752,547	$ 718,300
Expenses
Employee compensation and benefits	235,880	206,926	182,104
Depreciation and amortization	73,824	70,557	61,446
Technology and communications	72,166	62,801	52,964
Professional and consulting fees	27,382	31,935	33,949
Occupancy	14,690	14,216	14,121
General and administrative	22,709	23,042	19,200
Total expenses	476,227	437,528	391,424
Operating income	340,870	315,019	326,876
Other income (expense)
Interest expense	1,601	1,983	700
Equity in earnings of unconsolidated affiliate	1,395	735	1,126
Other, net	(6,164)	(3,496)	5,946
Total other income (expense)	19,676	17,681	11,412
Income before income taxes and equity in undistributed earnings of subsidiaries	360,546	332,700	338,288
Benefit from income taxes	86,365	74,645	88,064
Net income	274,181	258,055	250,224
Comprehensive income	263,852	271,382	225,857
MarketAxess Holdings Inc. (Parent) [Member]
Revenues	246,600	270,700	257,200
Expenses
Employee compensation and benefits	12,091	13,938	17,655
Depreciation and amortization	2,186	2,153	2,136
Professional and consulting fees	6,149	5,828	5,528
General and administrative	1,660	2,301	3,081
Total expenses	22,086	24,220	28,400
Operating income	224,514	246,480	228,800
Other income (expense)
Interest income	4,615	3,557	272
Interest expense	(167)	(155)	(271)
Equity in earnings of unconsolidated affiliate	1,395	735	1,126
Other, net	(5,088)	(369)	(2,633)
Total other income (expense)	755	3,768	(1,506)
Income before income taxes and equity in undistributed earnings of subsidiaries	225,269	250,248	227,294
Benefit from income taxes	(6,550)	(5,586)	(7,710)
Income before equity in undistributed income of subsidiaries	231,819	255,834	235,004
Equity in undistributed income of subsidiaries	42,362	2,221	15,220
Net income	274,181	258,055	250,224
Other comprehensive income (loss), net	(10,329)	13,327	(24,367)
Comprehensive income	$ 263,852	$ 271,382	$ 225,857

Parent Company Information - _3

Parent Company Information - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net Income (Loss)	$ 274,181	$ 258,055	$ 250,224
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	73,824	70,557	61,446
Amortization of operating lease right-of-use assets	6,639	5,853	5,708
Stock-based compensation expense	29,684	29,190	29,864
Deferred taxes	(3,878)	(5,815)	(6,547)
Other	7,042	(3,113)	555
Changes in operating assets and liabilities:
(Increase)/decrease in accounts receivable	(3,730)	(7,116)	(15,136)
Decrease/(increase) in prepaid expenses and other assets	1,009	(11,898)	(4,249)
(Decrease) increase in accrued employee compensation	7,049	1,466	(3,417)
Increase (decrease) in income and other tax liabilities	(3,284)	(14,691)	(4,768)
(Decrease)/increase in accounts payable, accrued expenses and other liabilities	3,543	(7,229)	11,384
(Decrease) in operating lease liabilities	(8,730)	(6,735)	(6,373)
Net cash provided by operating activities	385,237	333,767	289,231
Cash flows from investing activities
Acquisition of equity method investment	0	0	(34,400)
Proceeds from maturities and sales	12,440	4,452	0
Purchases	(42,810)	(28,818)	0
Purchases of furniture, equipment and leasehold improvements	(9,942)	(9,326)	(13,142)
Net cash (used in) investing activities	(86,935)	(155,290)	(86,272)
Cash flows from financing activities
Cash dividends on common stock	(112,697)	(109,658)	(105,942)
Exercise of stock options	2,988	940	672
Withholding tax payments on Full Value Awards vesting and stock option exercises	(16,194)	(25,839)	(23,404)
Repurchases of common stock	(75,474)	0	(87,540)
Proceeds from short-term borrowings	344,925	123,995	100,000
Repayments of short-term borrowings	(344,925)	(123,995)	(100,000)
Net cash (used in) financing activities	(201,377)	(147,057)	(242,378)
Effect of exchange rate changes on cash and cash equivalents	(8,138)	7,588	(13,484)
Cash and cash equivalents including restricted cash
Net increase for the period	88,787	39,008	(52,903)
Beginning of period	611,672	572,664	625,567
End of period	700,459	611,672	572,664
Supplemental cash flow information:
Cash paid for income taxes	96,932	94,814	88,677
Cash paid for interest	1,717	1,870	652
Non-cash investing and financing activity
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	1,840	1,183	1,880
Treasury stock used for acquisition of business	0	(43,841)	0
MarketAxess Holdings Inc. (Parent) [Member]
Cash flows from operating activities
Net Income (Loss)	274,181	258,055	250,224
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,186	2,153	2,136
Amortization of operating lease right-of-use assets	3,697	3,361	3,347
Stock-based compensation expense	7,130	9,725	12,554
Deferred taxes	397	101	(5,076)
Equity in undistributed income of subsidiaries	(42,362)	(2,221)	(15,220)
Other	4,304	(4,675)	441
Changes in operating assets and liabilities:
(Increase)/decrease in accounts receivable	526	(1,154)	(769)
Decrease in receivable from subsidiaries	12,694	5,474	7,931
Decrease/(increase) in prepaid expenses and other assets	304	1,296	(1,175)
(Decrease) increase in accrued employee compensation	1,118	(1,104)	(1,372)
(Increase) decrease in income and other tax receivables	(579)	3,800	(9,711)
Increase (decrease) in income and other tax liabilities	(2,278)	2,287	62
(Decrease)/increase in accounts payable, accrued expenses and other liabilities	4,809	(861)	443
(Decrease) in operating lease liabilities	(4,669)	(3,624)	(3,689)
Net cash provided by operating activities	261,364	272,424	241,110
Cash flows from investing activities
Acquisition of business	0	(81,161)	0
Acquisition of equity method investment	0	0	(34,400)
Investments in subsidiaries	(30)	(10,058)	(8,326)
Proceeds from maturities and sales	12,440	4,454	0
Purchases	(42,810)	(28,818)	0
Purchases of furniture, equipment and leasehold improvements	(156)	(239)	(96)
Net cash (used in) investing activities	(30,556)	(115,822)	(42,822)
Cash flows from financing activities
Cash dividends on common stock	(112,697)	(109,658)	(105,942)
Exercise of stock options	2,988	940	672
Withholding tax payments on Full Value Awards vesting and stock option exercises	(16,194)	(25,839)	(23,404)
Repurchases of common stock	(75,474)	0	(87,540)
Proceeds from short-term borrowings	100,000	100,000	100,000
Repayments of short-term borrowings	(100,000)	(100,000)	(100,000)
Net cash (used in) financing activities	(201,377)	(134,557)	(216,214)
Effect of exchange rate changes on cash and cash equivalents	0	(3)	15
Cash and cash equivalents including restricted cash
Net increase for the period	29,431	22,042	(17,911)
Beginning of period	65,951	43,909	61,820
End of period	95,382	65,951	43,909
Supplemental cash flow information:
Cash paid for income taxes	53,999	55,784	65,764
Cash paid for interest	167	35	271
Non-cash investing and financing activity
Exercise of stock options - cashless	1,735	0	3,845
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	0	1,072	0
Treasury stock used for acquisition of business	0	43,841	0
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
Decrease/(increase) in trading investments	(621)	(1,103)	1,813
Mutual Funds Held In Rabbi Trust [Member] | MarketAxess Holdings Inc. (Parent) [Member]
Changes in operating assets and liabilities:
Decrease/(increase) in trading investments	(94)	(189)	984
Trading Investments [Member]
Changes in operating assets and liabilities:
Decrease/(increase) in trading investments	$ (629)	$ (25,248)	$ (49,527)