MarketAxess (MKTX) 10-K 22 Feb 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2023	Feb. 20, 2024
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
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		37,867,743
Entity Public Float	$ 7.4
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 2024 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

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
ASSETS
Cash and cash equivalents	$ 451,280	$ 430,746
Cash segregated under federal regulations	45,122	50,947
Investments, at fair value	134,861	83,792
Accounts receivable, net of allowance of $577 and $590 as of December 31, 2023 and 2022 ,respectively	89,839	78,450
Receivables from broker-dealers, clearing organizations and customers	687,936	476,335
Goodwill	236,706	154,789
Intangible assets, net of accumulated amortization	119,108	98,065
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	102,671	100,256
Operating lease right-of-use assets	63,045	66,106
Prepaid expenses and other assets	84,499	68,289
Total assets	2,015,067	1,607,775
Liabilities
Accrued employee compensation	60,124	56,302
Payables to broker-dealers, clearing organizations and customers	537,398	303,993
Income and other tax liabilities	7,892	28,448
Accounts payable, accrued expenses and other liabilities	37,013	55,263
Operating lease liabilities	79,677	82,676
Total liabilities	722,104	526,682
Commitments and Contingencies (Note 15)
Stockholders' equity
Preferred stock	0	0
Common stock	123	123
Additional paid-in capital	333,292	345,468
Treasury stock - Common stock voting, at cost, 3,041,081 shares and 3,270,512 shares as of December 31, 2023 and 2022, respectively	(260,298)	(328,326)
Retained earnings	1,244,216	1,101,525
Accumulated other comprehensive loss	(24,370)	(37,697)
Total stockholders' equity	1,292,963	1,081,093
Total liabilities and stockholders' equity	2,015,067	1,607,775
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, 2023	Dec. 31, 2022
Allowance for accounts receivable	$ 577	$ 590
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	40,940,769	40,918,660
Common stock, shares outstanding	37,899,688	37,648,148
Treasury Stock, Common, Shares	3,041,081	3,270,512
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues
Revenues	$ 752,547	$ 718,300	$ 698,951
Expenses
Employee compensation and benefits	206,926	182,104	170,916
Depreciation and amortization	70,557	61,446	53,447
Technology and communications	62,801	52,964	42,474
Professional and consulting fees	31,935	33,949	41,925
Occupancy	14,216	14,121	13,320
Marketing and advertising	11,049	9,977	9,059
Clearing costs	17,002	17,663	16,074
General and administrative	23,042	19,200	14,501
Total expenses	437,528	391,424	361,716
Operating income	315,019	326,876	337,235
Other income (expense)
Interest income	22,425	5,040	401
Interest expense	(1,983)	(700)	(842)
Equity in earnings of unconsolidated affiliate	735	1,126	0
Other, net	(3,496)	5,946	(2,871)
Total other income (expense)	17,681	11,412	(3,312)
Income before income taxes	332,700	338,288	333,923
Provision for income taxes	74,645	88,064	76,035
Net income	$ 258,055	$ 250,224	$ 257,888
Net income per common share
Basic	$ 6.87	$ 6.68	$ 6.88
Diluted	6.85	6.65	6.77
Cash dividends declared per common share	$ 2.88	$ 2.8	$ 2.64
Weighted average shares outstanding
Basic	37,546	37,468	37,508
Diluted	37,654	37,643	38,097
Commissions [Member]
Revenues
Revenues	$ 662,964	$ 641,183	$ 621,008
Information Services [Member]
Revenues
Revenues	46,383	39,314	38,175
Post-trade Services [Member]
Revenues
Revenues	40,178	36,877	38,922
Technology Services [Member]
Revenues
Revenues	$ 3,022	$ 926	$ 846

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 258,055	$ 250,224	$ 257,888
Cumulative translation adjustment	13,349	(24,367)	(8,680)
Net unrealized (loss) on securities available-for-sale, net of tax of $12, $0 and $0, respectively	(22)	0	0
Comprehensive income	$ 271,382	$ 225,857	$ 249,208

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Securities available-for-sale, tax expense (benefit)	$ 12	$ 0	$ 0

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, 2020	$ 955,061	$ 123	$ 329,742	$ (169,523)	$ 799,369	$ (4,650)
Net Income (Loss)	257,888				257,888
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(8,680)					(8,680)
Stock-based compensation	27,314		27,314
Exercise of stock options	7,096		7,096
Withholding tax payments on restricted stock vesting and stock option exercises	(33,890)		(33,890)
Repurchases of common stock	(63,189)			(63,189)
Cash dividend on common stock	(100,291)				(100,291)
Ending 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 and foreign currency exchange hedge, net of tax	(24,367)					(24,367)
Stock-based compensation	29,864		29,864
Exercise of stock options	672		672
Withholding tax payments on restricted stock 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 and foreign currency exchange hedge, net of tax	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 restricted stock 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)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended			12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per common share	$ 0.72	$ 0.7	$ 0.66	$ 2.88	$ 2.8	$ 2.64

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net Income (Loss)	$ 258,055	$ 250,224	$ 257,888
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	70,557	61,446	53,447
Amortization of operating lease right-of-use assets	5,853	5,708	6,799
Stock-based compensation expense	29,190	29,864	27,314
Deferred taxes	(5,815)	(6,547)	3,118
Foreign currency transaction (gains) losses	4,718	(8,783)	0
Other	(3,113)	555	(466)
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(7,116)	(15,136)	15,598
(Increase) in receivables from broker-dealers, clearing organizations and customers	(181,044)	(47,631)	(156,909)
Decrease/(increase) in prepaid expenses and other assets	(11,898)	(4,249)	2,214
Increase/(decrease) in accrued employee compensation	1,466	(3,417)	(2,607)
Increase in payables to broker-dealers, clearing organizations and customers	227,920	74,668	95,999
(Decrease) in income and other tax liabilities	(14,691)	(4,768)	(5,638)
(Decrease)/increase in accounts payable, accrued expenses and other liabilities	(7,229)	11,384	215
(Decrease) in operating lease liabilities	(6,735)	(6,373)	(7,001)
Net cash provided by operating activities	333,767	289,231	282,091
Cash flows from investing activities
Proceeds from maturities and sales	4,452	0	0
Purchases	(28,818)	0	0
Acquisitions, net of cash and cash equivalents acquired	(78,476)	0	(17,078)
Acquisition of equity method investment	0	(34,400)	0
Purchases of furniture, equipment and leasehold improvements	(9,326)	(13,142)	(17,493)
Capitalization of software development costs	(43,122)	(38,730)	(33,123)
Net cash (used in) investing activities	(155,290)	(86,272)	(67,694)
Cash flows from financing activities
Cash dividend on common stock	(109,658)	(105,942)	(99,792)
Exercise of stock options	940	672	7,096
Withholding tax payments on restricted stock vesting and stock option exercises	(25,839)	(23,404)	(33,890)
Repurchases of common stock	0	(87,540)	(63,189)
Payment of contingent consideration	(12,500)	(26,164)	0
Proceeds from short-term borrowings	123,995	100,000	70,348
Repayments of short-term borrowings	(123,995)	(100,000)	(70,348)
Net cash (used in) financing activities	(147,057)	(242,378)	(189,775)
Effect of exchange rate changes on cash and cash equivalents	7,588	(13,484)	(7,105)
Cash and cash equivalents including restricted cash
Net increase (decrease) for the period	39,008	(52,903)	17,517
Beginning of period	572,664	625,567	608,050
End of period	611,672	572,664	625,567
Supplemental cash flow information:
Cash paid for income taxes	94,814	88,677	70,003
Cash paid for interest	1,870	652	830
Non-cash investing and financing activity:
Exercise of stock options - cashless	0	3,845	2,750
Right-of-use assets obtained in exchange for operating lease liabilities	1,183	1,880	1,972
Contingent consideration payable recognized in connection with acquisitions	0	0	27,947
Fair value of assets acquired	127,635	0	0
Cash paid for acquisition, net of cash and cash equivalents acquired	(78,476)	0	0
Treasury shares used for acquisition	(43,841)	0	0
Liabilities assumed	5,318	0	0
Trading Investments [Member]
Changes in operating assets and liabilities:
(Increase) in trading investments	(25,248)	(49,527)	(5,574)
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
(Increase) in trading investments	$ (1,103)	$ 1,813	$ (2,306)

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ 258,055	$ 250,224	$ 257,888

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	(b) Trading Plans In the fourth quarter of 2023, 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 7, 2023 , for the sale of up to 1,500 shares of the Company’s common stock, subject to certain conditions. The arrangement’s expiration date is February 18, 2025 .
Name	Scott Pintoff
Title	General Counsel & Corporate Secretary
Rule 10b5-1 Arrangement Adopted	true
Non-Rule 10b5-1 Arrangement Adopted	false
Adoption Date	December 7, 2023
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Termination Date	February 18, 2025
Arrangement Duration	439 days
Aggregate Available	1,500

Organization and Principal Busi

Organization and Principal Business Activity	12 Months Ended
	Dec. 31, 2023
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. Over 2,000 institutional investor and broker-dealer firms are active users of MarketAxess’ patented trading technology, accessing 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. 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. MarketAxess also offers a number of trading-related products and services, including: Composite+™ pricing and other market data products to assist clients with trading decisions; auto-execution and other execution services for clients requiring specialized workflow solutions; connectivity solutions that facilitate straight-through processing; and technology services to optimize trading environments. The Company also provides a range of pre- and post-trade services, including post-trade matching, trade publication, regulatory transaction reporting and market and reference data across a range of fixed-income and other products.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
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, foreign currency forward contracts and contingent consideration payables associated with acquisitions. 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 $ 0.6 million as of each of December 31, 2023 and 2022. The provision for bad debts was $ 0.4 million, $ 0.6 million and $ 0.2 million for the years ended December 31, 2023, 2022 and 2021, respectively. Write-offs and other charges against the allowance for credit losses were $ 0.3 million, $ 0.1 million and $ 0.1 million for the years ended December 31, 2023, 2022 and 2021, 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. The Company also earns other commissions on equities and foreign exchange products for algorithmic trading services. These fees may incorporate variable transaction fees, which are calculated as a percentage of the notional dollar volume traded, and distribution fees. The following table presents commission revenue by fee type : Year Ended December 31, 2023 2022 2021 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 323,038 $ 321,603 $ 333,712 Open Trading – matched principal trading 178,517 175,440 155,465 U.S. government bonds - matched principal trading 15,222 16,978 12,400 Other 4,979 — — Total variable transaction fees 521,756 514,021 501,577 Distribution fees and unused minimum fees 141,208 127,162 119,431 Total commissions $ 662,964 $ 641,183 $ 621,008 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, 2023 2022 2021 (In thousands) Information services revenue by timing of recognition Services transferred over time $ 45,102 $ 38,452 $ 37,341 Services transferred at a point in time 1,281 862 834 Total information services revenues $ 46,383 $ 39,314 $ 38,175 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, 2023 2022 2021 (In thousands) Post-trade services revenue by timing of recognition Services transferred over time $ 40,061 $ 36,835 $ 38,850 Services transferred at a point in time 117 42 72 Total post-trade services revenues $ 40,178 $ 36,877 $ 38,922 Technology services – Technology services revenue primarily includes technology services revenue generated by Pragma and revenue from telecommunications line charges to broker-dealer clients. 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, 2022 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2023 (In thousands) Information services $ 3,121 $ 12,715 $ ( 12,787 ) $ — $ 3,049 Post-trade services 869 23,116 ( 23,107 ) 45 923 Technology services — 1,085 ( 518 ) — 567 Total deferred revenue $ 3,990 $ 35,831 $ ( 35,894 ) $ 45 $ 4,539 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 $ 67.1 million as of December 31, 2023 . The Company expects to recognize revenue associated with the remaining performance obligations over the next 58 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.

Regulatory Capital Requirements

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2023
Broker-Dealer [Abstract]
Regulatory Capital Requirements	3. Regulatory Capital Requirements Certain of the Company’s U.S. subsidiaries are registered as broker-dealers and therefore are subject to the applicable rules and regulations of the SEC and FINRA. 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, 2023, 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, 2023, the Company’s subsidiaries maintained aggregate net capital and financial resources that were $ 605.4 million in excess of the required levels of $ 36.1 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, 2023, the U.S. broker-dealer subsidiary had a balance of $ 45.1 million in its special reserve bank account. This U.S. broker-dealer subsidiary also maintained net capital that was $ 306.3 million in excess of the required level of $ 9.3 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, 2023
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, 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 As of December 31, 2022 Assets Money market funds $ 59,173 $ — $ — $ 59,173 Trading securities U.S. Treasuries — 74,409 — 74,409 Mutual funds held in rabbi trust — 9,383 — 9,383 Total assets $ 59,173 $ 83,792 $ — $ 142,965 Liabilities Contingent consideration payable $ — $ — $ 12,340 $ 12,340 Foreign currency forward position — 1,688 — 1,688 Total liabilities $ — $ 1,688 $ 12,340 $ 14,028 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. Liabilities classified within Level 3 reflect contingent consideration payable recognized in connection with acquisitions. In May 2023, the Company made final payment on the remaining contingent consideration. The following table summarizes the change in the Company's Level 3 liabilities for the year ended December 31, 2023: December 31, 2022 Payments Realized (Gain)/Loss December 31, 2023 (In thousands) Contingent consideration payable $ 12,340 $ ( 12,500 ) $ 160 $ - 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, 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 As of December 31, 2022 Financial assets not measured at fair value: Cash $ 371,573 $ 371,573 $ 371,573 $ — $ — $ 371,573 Cash segregated under federal regulations 50,947 50,947 50,947 — — 50,947 Accounts receivable, net of allowance 78,450 78,450 — 78,450 — 78,450 Receivables from broker-dealers, clearing 476,335 476,335 88,923 387,412 — 476,335 Total $ 977,305 $ 977,305 $ 511,443 $ 465,862 $ — $ 977,305 Financial liabilities not measured at fair value: Payables to broker-dealers, clearing $ 303,993 $ 303,993 $ — $ 303,993 $ — $ 303,993 During the years ended December 31, 2023 and 2022 , there were no transfers between Level 1, Level 2 and Level 3 securities. 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 one- or 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, 2023 December 31, 2022 (In thousands) Notional value $ 61,858 $ 62,160 Fair value of notional 63,759 60,472 Fair value of the asset/(liability) $ 1,901 $ ( 1,688 ) Realized and unrealized gains and losses on foreign currency forward contracts are included in other, net in the Consolidated Statements of Operations. The Company recorded a net realized loss of $ 1.5 million and a net realized gain of $ 0.8 million for the years ended December 31, 2023 and 2022, respectively. The Company recorded a net unrealized gain of $ 3.6 million and a net unrealized loss of $ 1.7 million for the years ended December 31 2023 and 2022, respectively. The Company records collateral deposits with its counterparty bank in prepaid expenses and other assets on the Consolidated Statements of Financial Condition. As of December 31, 2023, the Company did not maintain a collateral deposit with its counterparty bank. The following table summarizes the Company’s investments: Amortized Gross Gross Fair (In thousands) 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 As of December 31, 2022 Trading securities U.S. Treasuries $ 74,943 $ — $ ( 534 ) $ 74,409 Mutual funds held in rabbi trust 11,474 — ( 2,091 ) 9,383 Total investments $ 86,417 $ — $ ( 2,625 ) $ 83,792 Proceeds from the sales and maturities of investments were $ 29.5 million and $ 19.4 million for the years ended December 31, 2023 and 2021, respectively. There were no proceeds from the sales and maturities of investments during the year ended December 31, 2022. Purchases of investments were $ 78.6 million, $ 50.1 million and $ 25.0 million for the years ended December 31, 2023, 2022 and 2021, respectively. The following table summarizes the Company’s unrealized and realized gains and losses on investments: Year ended December 31, 2023 2022 2021 (In thousands) Unrealized gains/(losses) Securities available-for-sale Corporate debt $ ( 11 ) $ — $ — Trading securities U.S. Treasuries 446 ( 534 ) ( 111 ) Mutual funds held in rabbi trust 1,284 ( 2,091 ) 1,254 Total investments $ 1,719 $ ( 2,625 ) $ 1,143 Realized gains/(losses) Securities available-for-sale Corporate debt $ ( 11 ) $ — $ — Trading securities Corporate debt — — 89 Mutual funds held in rabbi trust ( 138 ) — — Total investments $ ( 149 ) $ — $ 89 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 investments based upon the contractual maturities: Less than one year Due in 1 - 5 years Total (In thousands) 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 Mutual funds held in rabbi trust 10,485 — 10,485 Total $ 70,968 $ 63,893 $ 134,861 As of December 31, 2022 Trading securities U.S. Treasuries $ 24,618 $ 49,791 $ 74,409 Mutual funds held in rabbi trust 9,383 — 9,383 Total $ 34,001 $ 49,791 $ 83,792 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 as of December 31, 2023: 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, 2023 Corporate debt $ 17,658 $ ( 66 ) $ — $ — $ 17,658 $ ( 66 ) During the years ended December 31, 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, 2023
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, 2023 December 31, 2022 Receivables from broker-dealers, clearing organizations and customers: (In thousands) Securities failed-to-deliver – broker-dealers and clearing organizations $ 282,125 $ 144,523 Securities failed-to-deliver – customers 284,322 235,056 Deposits with clearing organizations and broker-dealers 115,151 88,923 Other 6,338 7,833 Total $ 687,936 $ 476,335 Payables to broker-dealers, clearing organizations and customers: Securities failed-to-receive – broker-dealers and clearing organizations $ 125,022 $ 224,816 Securities failed-to-receive – customers 405,186 71,828 Other 7,190 7,349 Total $ 537,398 $ 303,993

Acquisitions and Equity Investm

Acquisitions and Equity Investments	12 Months Ended
	Dec. 31, 2023
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 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 are prohibited from transferring any of the Company common stock received in the 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, 2023 , the Company’s investment is recorded at carrying value of $ 36.3 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 $ 0.7 million and $ 1.1 million for the years ended December 31, 2023 and 2022, respectively, and is recorded within equity in earnings of unconsolidated affiliate on the Consolidated Statements of Operations. 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 amount billed for the year ended December 31, 2023 was $ 1.1 million and is included within other, net on the Consolidated Statements of Operations. The receivable from the equity method investee was $ 1.1 million as of December 31, 2023 and is included within accounts receivable, net on the Consolidated Statements of Financial Condition. Acquisition of MuniBrokers LLC On April 9, 2021, the Company acquired MuniBrokers LLC, a central electronic venue serving municipal bond brokers and dealers. As part of the purchase price, the Company recorded $ 22.5 million of contingent consideration payable, which was included within accounts payable, accrued expenses, and other liabilities on the Consolidated Statements of Financial Condition. In May 2022, the Company made a payment of $ 8.3 million to settle the first earn-out period consideration. In May 2023, the Company made a payment of $ 12.5 million to settle the second earn-out period consideration. As of December 31, 2023, the Company had no remaining outstanding contingent consideration payable .

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2023
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 and $ 154.8 million as of December 31, 2023 and 2022, respectively. The following is a summary of changes in goodwill and intangible assets for the year ended December 31, 2023: (In thousands) Balance at December 31, 2022 $ 154,789 Goodwill from Pragma Acquisition 81,917 Balance at December 31, 2023 $ 236,706 Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2023 December 31, 2022 Cost Accumulated Net carrying Cost Accumulated Net carrying (In thousands) Customer relationships $ 140,348 $ ( 50,987 ) $ 89,361 $ 129,991 $ ( 34,310 ) $ 95,681 Technology and other intangibles 41,130 ( 11,383 ) 29,747 11,430 ( 9,046 ) 2,384 Total $ 181,478 $ ( 62,370 ) $ 119,108 $ 141,421 $ ( 43,356 ) $ 98,065 Amortization expense associated with identifiable intangible assets was $ 18.6 million, $ 16.4 million and $ 13.4 million for the years ended December 31, 2023, 2022 and 2021, respectively. Annual estimated total amortization expense is $ 19.9 million, $ 17.0 million, $ 15.3 million, $ 13.9 million and $ 12.3 million for the years ended December 31, 2024 through 2028, respectively.

Capitalized Software, Furniture

Capitalized Software, Furniture, Equipment and Leasehold Improvements	12 Months Ended
	Dec. 31, 2023
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, 2023 2022 (In thousands) Software development costs $ 261,850 $ 218,848 Computer hardware and related software 42,913 37,614 Office hardware 7,609 8,455 Furniture and fixtures 6,508 6,952 Leasehold improvements 31,214 30,660 350,094 302,529 Accumulated depreciation and amortization ( 247,423 ) ( 202,273 ) Total $ 102,671 $ 100,256 During the years ended December 31, 2023 and 2022, software development costs totaling $ 43.1 million and $ 38.7 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, 2023
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes The provision for income taxes consists of the following: Year Ended December 31, 2023 2022 2021 (In thousands) Current: Federal $ 49,028 $ 52,865 $ 36,661 State and local 4,047 20,716 17,238 Foreign 27,385 21,030 19,018 Total current provision 80,460 94,611 72,917 Deferred: Federal ( 2,823 ) ( 5,830 ) 2,249 State and local ( 754 ) ( 1,350 ) 778 Foreign ( 2,238 ) 633 91 Total deferred provision ( 5,815 ) ( 6,547 ) 3,118 Provision for income taxes $ 74,645 $ 88,064 $ 76,035 Pre-tax income from U.S. operations was $ 228.8 million, $ 236.4 million and $ 234.6 million for the years ended December 31, 2023, 2022 and 2021, respectively. Pre-tax income from foreign operations was $ 103.9 million, $ 101.9 million and $ 99.3 million for the years ended December 31, 2023, 2022 and 2021, 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, 2023 2022 2021 U.S. federal statutory tax rate 21.0 % 21.0 % 21.0 % State and local taxes - net of federal benefit 0.8 4.6 4.4 Tax credits ( 1.0 ) ( 0.4 ) ( 0.4 ) Foreign rate differential benefit 0.9 ( 0.1 ) ( 0.2 ) Excess tax benefit from stock-based compensation 0.1 ( 0.1 ) ( 2.9 ) Other, net 0.6 1.0 0.9 Effective tax rate 22.4 % 26.0 % 22.8 % The following is a summary of the Company’s net deferred tax assets: As of December 31, 2023 2022 (In thousands) Deferred tax assets: Stock compensation expense $ 4,441 $ 3,451 Operating lease liabilities 17,128 17,842 Deferred Compensation 2,596 2,425 Other 1,015 1,774 Total deferred tax assets 25,180 25,492 Valuation allowance — — Net deferred tax assets 25,180 25,492 Deferred tax liabilities: Depreciation ( 8,617 ) ( 9,956 ) Capitalized software development costs — ( 3,923 ) Goodwill and intangible assets ( 3,987 ) ( 4,829 ) Operating lease right-of-use assets ( 13,507 ) ( 14,176 ) Other deferred tax liabilities ( 276 ) — Deferred tax (liability) asset, net $ ( 1,207 ) $ ( 7,392 ) The Company or one of its subsidiaries files U.S. federal, state and foreign income tax returns. In 2022, the Company settled its New York State income tax examination for tax years 2010 through 2014 and is currently under a New York State income tax examination for tax years 2015 through 2017 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 unrecognized tax benefits is as follows: Year Ended December 31, 2023 2022 2021 (In thousands) Balance at beginning of year $ 9,835 $ 15,089 $ 16,317 Increase/(decrease) based on tax positions related to prior periods — 160 ( 1,228 ) (Decrease) related to settlements with taxing authorities ( 6,705 ) ( 5,414 ) — Balance at end of year $ 3,130 $ 9,835 $ 15,089 As of December 31, 2023, the Company recorded $ 3.1 million of net unrecognized tax benefits which, if recognized, would affect the Company’s effective tax rate. The Company estimates that this remaining unrecognized tax benefit will be settled within the next 12 months. However, due to the uncertainty related to the timing and potential outcome of the audits, the Company cannot reasonably estimate the amount of any additional unrecognized tax benefit that could be adjusted in the next 12 months. During the years ended December 31, 2023, 2022 and 2021, the Company recognized gross expenses of $ 1.6 million, $ 5.8 million and $ 3.3 million, respectively, in penalties and interest. The Company had $ 2.6 million and $ 7.9 million accrued for the payment of interest and penalties as of December 31, 2023 and 2022, respectively. 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, 2023
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Equity Common Stock As of December 31, 2023 , 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: December 31, 2023 2023 2022 2021 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,648 37,919 38,005 Exercise of stock options 6 29 92 Issuance of restricted stock and performance shares, net of cancellations 97 66 48 Shares withheld for withholding tax payments ( 81 ) ( 86 ) ( 75 ) Repurchases — ( 280 ) ( 151 ) Reissuance of treasury stock 5 — — Treasury stock used for acquisition 225 — — Outstanding shares of voting common stock at the end of year 37,900 37,648 37,919 In January 2019, the Board authorized a two-year share repurchase program for up to $ 100.0 million, which commenced in April 2019 and expired in March 2021 . In January 2021, the Board authorized a share repurchase program for up to $ 100.0 million that commenced in April 2021 and was completed in January 2022 . In January 2022, the Board authorized a share repurchase program for up to $ 150.0 million. Shares repurchased under each program will be held in treasury for future use. Dividends During 2023, 2022 and 2021, the Company paid quarterly cash dividends of $ 0.72 per share, $ 0.70 per share and $ 0.66 per share, respectively. Any future declaration and payment of dividends will be at the sole discretion of the Company’s 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, 2023
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 stock options, restricted stock, restricted stock units, performance shares, performance stock units 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, 2023, there were 2,436,113 shares available for grant under the 2020 Plan. 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 expense was as follows: Year Ended December 31, 2023 2022 2021 (In thousands) Employees Restricted stock, restricted stock units, performance shares $ 24,205 $ 24,593 $ 23,041 Stock options 3,592 3,583 2,961 27,797 28,176 26,002 Non-employee directors Restricted stock and restricted stock units 1,393 1,688 1,312 Total stock-based compensation $ 29,190 $ 29,864 $ 27,314 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 or five -year period. Options generally expire in six or ten 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 highly 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, 2023, 2022 and 2021 were $ 123.47 , $ 101.38 and $ 137.66 , 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, excluding the two awards based on the Monte Carlo model discussed below: Year Ended December 31, 2023 2022 2021 Expected life (years) 5.0 5.0 5.0 Risk-free interest rate 3.6 % 1.5 % 0.4 % Expected volatility 35.8 % 32.6 % 31.2 % Expected dividend yield 0.8 % 0.7 % 0.4 % In addition to the stock option grants above, the Company granted 148,524 and 76,868 premium-priced stock options to the Company’s then-Chief Executive Officer and then-President and Chief Operating Officer in November 2018 and January 2019, respectively. The stock options vested in November 2023 and January 2024, respectively. The fair value of each option award was estimated on the date of grant using the Monte Carlo model. The following table reports stock option activity during the years ended December 31, 2023, 2022 and 2021 and the intrinsic value as of December 31, 2023, 2022 and 2021: Number Weighted-Average Exercise Price ($) Remaining Intrinsic Value ($) (In thousands) Outstanding at December 31, 2020 387,372 223.60 Granted 17,897 517.88 Canceled ( 616 ) 394.77 Exercised ( 91,900 ) 107.05 Outstanding at December 31, 2021 312,753 274.35 Granted 23,904 352.15 Canceled ( 1,646 ) 421.08 Exercised ( 28,758 ) 157.08 Outstanding at December 31, 2022 306,253 290.65 Granted 13,908 358.53 Canceled ( 551 ) 382.12 Exercised ( 5,653 ) 166.34 761 Outstanding at December 31, 2023 313,957 295.74 1.1 6,214 Exercisable at December 31, 2023 202,562 285.35 0.7 5,502 The intrinsic value is the amount by which the closing price of the Company’s common stock on December 31, 2023 of $ 292.85 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, 2023, there was $ 2.2 million of total unrecognized compensation cost related to non-vested stock options. That cost is expected to be recognized over a weighted-average period of 0.5 years. Annual 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 are 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- or four-year period. In addition, the Company grants share-based compensation awards to its non-employee directors as part of such directors’ compensation. These awards generally vest on the date of the Company’s next annual stockholders’ meeting, subject to continued service to the Company. Such share-based compensation awards are expensed over the requisite service period. Annual Performance-based Performance Shares and Performance Stock Unit Awards The Company grants performance equity 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 equity 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 employment with the Company. The Company has also previously granted performance-based awards with a five-year vesting period that vested in November 2023 and January 2024. In January 2021, annual performance equity awards were granted with a three-year performance period that would vest based on the level of achievement by the Company of certain predetermined metrics, including pre-tax adjusted operating margin and market share for the years ended December 31, 2021, 2022 and 2023, subject to continued service with the Company through the vesting date. In January 2024, the Company’s Compensation and Talent Committee of the Board certified the Company’s performance against such metrics at 38.9 %. Compensation expense for the three-year performance equity awards 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. In January 2022 and February 2023, 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 and 2023 will range from zero to 200 %. Subject to the grantee’s continued service, any performance equity 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 The Company granted 37,742 and 18,914 performance shares to the Company’s then-Chief Executive Officer and then-President and Chief Operating Officer in November 2018 and January 2019, respectively. The performance shares vested in November 2023 and January 2024, respectively. In August 2021, the Company’s then-Chief Financial Officer received a one-time equity award in connection with his promotion to Chief Financial Officer consisting, in part, of a performance stock unit award with a target of 1,070 shares. The award was scheduled to vest on August 1, 2024, but was forfeited upon the termination of his employment in January 2024. 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 employment through such date. 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. Performance Equity Award Estimates The following table reports the Company's performance payout estimates for three-year performance period awards as of December 31, 2023, as well as the target and maximum share payouts for each award date granted: Award Date 2023 Estimate Target Maximum January 15, 2021 4,739 12,185 24,370 August 1, 2021 437 1,070 2,140 January 31, 2022 11,343 18,155 36,310 March 1, 2022 2,490 3,986 7,972 February 15, 2023 14,178 18,263 36,526 Equity Grant Activity The following table reports restricted stock, restricted stock unit, performance share and performance stock unit activity during the years ended December 31, 2023, 2022 and 2021: Number of Restricted Shares Weighted-Average Grant Date Fair Value Outstanding at December 31, 2020 230,647 $ 224.63 Granted 47,142 Performance share pay-out — Canceled ( 3,911 ) Vested ( 111,268 ) 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 As of December 31, 2023, there was $ 38.4 million of total unrecognized compensation cost related to non-vested restricted stock, restricted stock units, performance shares, and performance stock units. That cost is expected to be recognized over a weighted-average period of 1.5 years. Employee Stock Purchase Plans 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. For the year ended December 31, 2023, the Company issued 4,655 shares of common stock under the ESPP. As of December 31, 2023, there were 116,566 shares available for purchase under the ESPP.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2023
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, 2023 2022 2021 (In thousands, except per share amounts) Basic weighted average shares outstanding 37,546 37,468 37,508 Dilutive effect of stock options and restricted stock 108 175 589 Diluted weighted average shares outstanding 37,654 37,643 38,097 Basic earnings per share $ 6.87 $ 6.68 $ 6.88 Diluted earnings per share 6.85 6.65 6.77 Stock options and restricted stock totaling 306,678 shares, 310,447 shares and 41,240 shares for the years ended December 31, 2023, 2022 and 2021, 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, 2023
Debt Disclosure [Abstract]
Credit Agreements and Short-term Financing	13. Credit Agreements and Short-term Financing 2021 Credit Agreement On October 15, 2021, the Company entered into a three -year revolving credit facility (the “2021 Credit Agreement”) provided by a syndicate of lenders and JPMorgan Chase Bank, N.A., as administrative agent , which provided aggregate commitments totaling $ 500.0 million, including a revolving credit facility, a $ 5.0 million letter of credit sub-limit for standby letters of credit and a $ 50.0 million sub-limit for swingline loans. The 2021 Credit Agreement was scheduled to mature on October 15, 2024 , but was replaced by the 2023 Credit Agreement (as defined below). The 2021 Credit Agreement required that the Company satisfy certain covenants, including a requirement to not exceed a maximum consolidated total leverage ratio. The Company incurred $ 0.1 million and $ 0.3 million of interest expense under the 2021 Credit Agreement for the years ended December 31, 2023 and 2022, respectively. The Company did no t incur any interest expense under the 2021 Credit Agreement for the year ended December 31, 2021. 2023 Credit Agreement On August 9, 2023, the Company replaced the 2021 Credit Agreement with a new three-year revolving credit facility (the “2023 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 2023 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 2023 Credit Agreement by up to $ 375.0 million in total . As of December 31, 2023, the Company had $ 0.1 million in letters of credit outstanding and $ 749.9 million in available borrowing capacity under the 2023 Credit Agreement. Borrowings under the 2023 Credit Agreement will bear interest at a rate per annum equal to the 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 2023 Credit Agreement requires that the Company satisfy certain covenants, including a requirement not to exceed a maximum consolidated total leverage ratio. The Company incurred $ 0.1 million of interest expense under the 2023 Credit Agreement for the year ended December 31, 2023. 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, 2023 and 2021 , and no interest expense on borrowings under such agreements during the year ended December 31, 2022. As of December 31, 2023 , 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 $ 0.7 million, $ 0.4 million and $ 0.8 million during the years ended December 31, 2023, 2022 and 2021, respectively. As of December 31, 2023 , the Company had no overdrafts payable outstanding.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021 : Year Ended December 31, Lease cost: Classification 2023 2022 2021 (In thousands) Operating lease cost - office space Occupancy $ 12,861 $ 13,015 $ 13,202 Operating lease cost for subleased/assigned properties Other, net — 469 2,054 Operating lease cost - equipment Technology and communications 98 — — Variable lease costs Occupancy 237 96 13 Sublease income Other, net — ( 405 ) ( 2,079 ) Net operating lease cost $ 13,196 $ 13,175 $ 13,190 Finance lease expense was $ 0.1 million for the year ended December 31, 2023. 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, 2023 December 31, 2022 Weighted average remaining lease term (in years) - operating leases 9.6 10.6 Weighted average discount rate - operating leases 6.0 % 5.9 % Weighted average remaining lease term (in years) - finance leases 1.8 — Weighted average discount rate - finance leases 7.2 % — The following table presents the maturity of lease liabilities as of December 31, 2023: Operating Leases Finance Leases (In thousands) 2024 $ 12,986 $ 117 2025 12,093 88 2026 11,521 — 2027 8,956 — 2028 8,602 — 2029 and thereafter 51,269 — Total lease payments 105,427 205 Less: imputed interest 25,750 13 Present value of lease liabilities $ 79,677 $ 192

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021, 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, 2023
Segment Reporting [Abstract]
Segment and Geographic Information	16. Segment and Geographic Information The Company operates electronic platforms for the trading of fixed-income securities and provides related data, analytics, compliance tools, post-trade services and technology services. The Company considers its operations to constitute a single business segment because of the highly integrated nature of these products and services, the financial markets in which the Company competes and the Company’s worldwide business activities. The Company believes that results by geographic region or client sector are not necessarily meaningful in understanding its business. For the years ended December 31, 2023, 2022 and 2021, the U.K. was the only individual foreign country in which the Company had a subsidiary that accounted for 10 % 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 particular subsidiary. Long-lived assets are defined as furniture, equipment, leasehold improvements and capitalized software . Revenues for the years ended December 31, 2023, 2022 and 2021, and long-lived assets as of December 31, 2023 and 2022 were as follows: Year Ended December 31, 2023 2022 2021 (In thousands) Revenues Americas $ 597,145 $ 581,935 $ 568,918 Europe 136,989 119,112 110,068 Asia 18,413 17,253 19,965 Total $ 752,547 $ 718,300 $ 698,951 As of December 31, 2023 December 31, 2022 (In thousands) Long-lived assets, as defined Americas $ 87,513 $ 82,008 Europe 14,717 17,723 Asia 441 525 Total $ 102,671 $ 100,256

Retirement and Deferred Compens

Retirement and Deferred Compensation Plans	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021, respectively, the Company contributed $ 7.6 million, $ 6.1 million and $ 5.8 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, 2023 and 2022, the fair value of the mutual fund investments and deferred compensation obligations were $ 10.5 million and $ 9.4 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, 2023
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 2023 2022 2021 (In thousands) Cash and cash equivalents Cash and cash equivalents $ 451,280 $ 430,746 $ 506,735 Cash segregated for regulatory Cash segregated under federal 45,122 50,947 50,159 Deposits with clearing organizations Receivables from broker-dealers, 115,151 88,923 68,565 Other deposits Prepaid expenses and other assets 119 2,048 108 Total $ 611,672 $ 572,664 $ 625,567

Parent Company Information

Parent Company Information	12 Months Ended
	Dec. 31, 2023
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, 2023 December 31, 2022 (In thousands) ASSETS Cash and cash equivalents $ 65,951 $ 43,909 Investments, at fair value 30,225 5,343 Accounts receivable 1,923 769 Receivable from subsidiaries 18,010 8,962 Intangible assets, net of accumulated amortization 21 23 Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization 17,644 19,557 Operating lease right-of-use assets 55,113 57,402 Investments in subsidiaries 1,140,798 985,222 Prepaid expenses and other assets 45,140 41,511 Income and other tax receivable 7,674 11,474 Total assets $ 1,382,499 $ 1,174,172 LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities Accrued employee compensation 8,589 $ 9,693 Income and other tax liabilities 3,000 12 Accounts payable, accrued expenses and other liabilities 8,212 11,087 Operating lease liabilities 69,735 72,287 Total liabilities 89,536 93,079 Stockholders' equity Preferred stock — — Series A Preferred Stock — — Common stock voting 123 123 Common stock non-voting — — Additional paid-in capital 333,292 345,468 Treasury stock ( 260,298 ) ( 328,326 ) Retained earnings 1,244,216 1,101,525 Accumulated other comprehensive loss ( 24,370 ) ( 37,697 ) Total stockholders' equity 1,292,963 1,081,093 Total liabilities and stockholders' equity $ 1,382,499 $ 1,174,172 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations Year Ended December 31, 2023 2022 2021 (In thousands) Revenues $ 270,700 $ 257,200 $ 173,000 Expenses Employee compensation and benefits 13,938 17,655 17,887 Depreciation and amortization 2,153 2,136 2,123 Professional and consulting fees 5,828 5,528 7,081 General and administrative 2,301 3,081 3,620 Total expenses 24,220 28,400 30,711 Operating income 246,480 228,800 142,289 Other income (expense) Interest income 3,557 272 132 Interest expense ( 155 ) ( 271 ) — Equity in earnings of unconsolidated affiliate 735 1,126 — Other, net ( 369 ) ( 2,633 ) ( 2,950 ) Total other income (expense) 3,768 ( 1,506 ) ( 2,818 ) Income before income taxes and equity in undistributed earnings of subsidiaries 250,248 227,294 139,471 Benefit from income taxes ( 5,586 ) ( 7,710 ) ( 6,472 ) Income before equity in undistributed income of subsidiaries 255,834 235,004 145,943 Equity in undistributed income of subsidiaries 2,221 15,220 111,945 Net income 258,055 250,224 257,888 Other comprehensive income (loss), net 13,327 ( 24,367 ) ( 8,680 ) Comprehensive income $ 271,382 $ 225,857 $ 249,208 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2023 2022 2021 (In thousands) Cash flows from operating activities Net income $ 258,055 $ 250,224 $ 257,888 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 2,153 2,136 2,123 Amortization of operating lease right-of-use assets 3,361 3,347 4,484 Stock-based compensation expense 9,725 12,554 12,706 Deferred taxes 101 ( 5,076 ) 1,712 Equity in undistributed income of subsidiaries ( 2,221 ) ( 15,220 ) ( 111,945 ) Other ( 4,675 ) 441 — Changes in operating assets and liabilities: (Increase)/decrease in accounts receivable ( 1,154 ) ( 769 ) 178 Decrease in receivable from subsidiaries 5,474 7,931 47,371 Decrease/(increase) in prepaid expenses and other assets 1,296 ( 1,175 ) ( 219 ) (Increase)/decrease in mutual funds held in rabbi trust ( 189 ) 984 ( 1,516 ) (Decrease)/increase in accrued employee compensation ( 1,104 ) ( 1,372 ) 824 (Increase)/decrease in income and other tax receivables 3,800 ( 9,711 ) 7,265 Increase/(decrease) increase in income and other tax liabilities 2,287 62 ( 143 ) (Decrease)/increase in accounts payable, accrued expenses and other liabilities ( 861 ) 443 ( 607 ) (Decrease) in operating lease liabilities ( 3,624 ) ( 3,689 ) ( 4,673 ) Net cash provided by operating activities 272,424 241,110 215,449 Cash flows from investing activities Acquisition of business, net of cash and cash equivalents acquired ( 81,161 ) — ( 17,079 ) Acquisition of equity method investment — ( 34,400 ) — Investments in subsidiaries ( 10,058 ) ( 8,326 ) — Available-for-sale investments Proceeds from maturities and sales 4,454 — — Purchases ( 28,818 ) — — Purchases of furniture, equipment and leasehold improvements ( 239 ) ( 96 ) ( 198 ) Net cash (used in) investing activities ( 115,822 ) ( 42,822 ) ( 17,277 ) Cash flows from financing activities Cash dividend on common stock ( 109,658 ) ( 105,942 ) ( 99,791 ) Exercise of stock options 940 672 7,096 Withholding tax payments on restricted stock vesting and stock option exercises ( 25,839 ) ( 23,404 ) ( 33,890 ) Repurchases of common stock — ( 87,540 ) ( 63,189 ) Proceeds from short-term borrowings 100,000 100,000 — Repayments of short-term borrowings ( 100,000 ) ( 100,000 ) — Net cash (used in) financing activities ( 134,557 ) ( 216,214 ) ( 189,774 ) Effect of exchange rate changes on investments ( 3 ) 15 ( 2,324 ) Cash and cash equivalents including restricted cash Net increase (decrease) for the period 22,042 ( 17,911 ) 6,073 Beginning of period 43,909 61,820 55,747 End of period $ 65,951 $ 43,909 $ 61,820 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows (Continued) Year Ended December 31, 2023 2022 2021 (In thousands) Supplemental cash flow information: Cash paid for income taxes $ 55,784 $ 65,764 $ 41,103 Cash paid for interest 35 271 — Non-cash investing and financing activity: Exercise of stock options - cashless $ — $ 3,845 $ 2,750 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, 2023
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, foreign currency forward contracts and contingent consideration payables associated with acquisitions. 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 $ 0.6 million as of each of December 31, 2023 and 2022. The provision for bad debts was $ 0.4 million, $ 0.6 million and $ 0.2 million for the years ended December 31, 2023, 2022 and 2021, respectively. Write-offs and other charges against the allowance for credit losses were $ 0.3 million, $ 0.1 million and $ 0.1 million for the years ended December 31, 2023, 2022 and 2021, 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. The Company also earns other commissions on equities and foreign exchange products for algorithmic trading services. These fees may incorporate variable transaction fees, which are calculated as a percentage of the notional dollar volume traded, and distribution fees. The following table presents commission revenue by fee type : Year Ended December 31, 2023 2022 2021 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 323,038 $ 321,603 $ 333,712 Open Trading – matched principal trading 178,517 175,440 155,465 U.S. government bonds - matched principal trading 15,222 16,978 12,400 Other 4,979 — — Total variable transaction fees 521,756 514,021 501,577 Distribution fees and unused minimum fees 141,208 127,162 119,431 Total commissions $ 662,964 $ 641,183 $ 621,008 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, 2023 2022 2021 (In thousands) Information services revenue by timing of recognition Services transferred over time $ 45,102 $ 38,452 $ 37,341 Services transferred at a point in time 1,281 862 834 Total information services revenues $ 46,383 $ 39,314 $ 38,175 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, 2023 2022 2021 (In thousands) Post-trade services revenue by timing of recognition Services transferred over time $ 40,061 $ 36,835 $ 38,850 Services transferred at a point in time 117 42 72 Total post-trade services revenues $ 40,178 $ 36,877 $ 38,922 Technology services – Technology services revenue primarily includes technology services revenue generated by Pragma and revenue from telecommunications line charges to broker-dealer clients. 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, 2022 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2023 (In thousands) Information services $ 3,121 $ 12,715 $ ( 12,787 ) $ — $ 3,049 Post-trade services 869 23,116 ( 23,107 ) 45 923 Technology services — 1,085 ( 518 ) — 567 Total deferred revenue $ 3,990 $ 35,831 $ ( 35,894 ) $ 45 $ 4,539 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 $ 67.1 million as of December 31, 2023 . The Company expects to recognize revenue associated with the remaining performance obligations over the next 58 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.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Commission Revenue by Fee Type	The following table presents commission revenue by fee type : Year Ended December 31, 2023 2022 2021 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 323,038 $ 321,603 $ 333,712 Open Trading – matched principal trading 178,517 175,440 155,465 U.S. government bonds - matched principal trading 15,222 16,978 12,400 Other 4,979 — — Total variable transaction fees 521,756 514,021 501,577 Distribution fees and unused minimum fees 141,208 127,162 119,431 Total commissions $ 662,964 $ 641,183 $ 621,008
Summary of Information Services Revenue by Timing of Recognition	The following table presents information services revenue by timing of recognition: Year Ended December 31, 2023 2022 2021 (In thousands) Information services revenue by timing of recognition Services transferred over time $ 45,102 $ 38,452 $ 37,341 Services transferred at a point in time 1,281 862 834 Total information services revenues $ 46,383 $ 39,314 $ 38,175
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, 2023 2022 2021 (In thousands) Post-trade services revenue by timing of recognition Services transferred over time $ 40,061 $ 36,835 $ 38,850 Services transferred at a point in time 117 42 72 Total post-trade services revenues $ 40,178 $ 36,877 $ 38,922
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, 2022 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2023 (In thousands) Information services $ 3,121 $ 12,715 $ ( 12,787 ) $ — $ 3,049 Post-trade services 869 23,116 ( 23,107 ) 45 923 Technology services — 1,085 ( 518 ) — 567 Total deferred revenue $ 3,990 $ 35,831 $ ( 35,894 ) $ 45 $ 4,539

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
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, 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 As of December 31, 2022 Assets Money market funds $ 59,173 $ — $ — $ 59,173 Trading securities U.S. Treasuries — 74,409 — 74,409 Mutual funds held in rabbi trust — 9,383 — 9,383 Total assets $ 59,173 $ 83,792 $ — $ 142,965 Liabilities Contingent consideration payable $ — $ — $ 12,340 $ 12,340 Foreign currency forward position — 1,688 — 1,688 Total liabilities $ — $ 1,688 $ 12,340 $ 14,028
Summary of the Change in the Company's Contingent Consideration Payable	year ended December 31, 2023: December 31, 2022 Payments Realized (Gain)/Loss December 31, 2023 (In thousands) Contingent consideration payable $ 12,340 $ ( 12,500 ) $ 160 $ -
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, 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 As of December 31, 2022 Financial assets not measured at fair value: Cash $ 371,573 $ 371,573 $ 371,573 $ — $ — $ 371,573 Cash segregated under federal regulations 50,947 50,947 50,947 — — 50,947 Accounts receivable, net of allowance 78,450 78,450 — 78,450 — 78,450 Receivables from broker-dealers, clearing 476,335 476,335 88,923 387,412 — 476,335 Total $ 977,305 $ 977,305 $ 511,443 $ 465,862 $ — $ 977,305 Financial liabilities not measured at fair value: Payables to broker-dealers, clearing $ 303,993 $ 303,993 $ — $ 303,993 $ — $ 303,993
Summary of Foreign Currency Forward Contracts	The following table summarizes the Company’s foreign currency forward position: As of December 31, 2023 December 31, 2022 (In thousands) Notional value $ 61,858 $ 62,160 Fair value of notional 63,759 60,472 Fair value of the asset/(liability) $ 1,901 $ ( 1,688 )
Summary of Company's Investments	The following table summarizes the Company’s investments: Amortized Gross Gross Fair (In thousands) 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 As of December 31, 2022 Trading securities U.S. Treasuries $ 74,943 $ — $ ( 534 ) $ 74,409 Mutual funds held in rabbi trust 11,474 — ( 2,091 ) 9,383 Total investments $ 86,417 $ — $ ( 2,625 ) $ 83,792
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, 2023 2022 2021 (In thousands) Unrealized gains/(losses) Securities available-for-sale Corporate debt $ ( 11 ) $ — $ — Trading securities U.S. Treasuries 446 ( 534 ) ( 111 ) Mutual funds held in rabbi trust 1,284 ( 2,091 ) 1,254 Total investments $ 1,719 $ ( 2,625 ) $ 1,143 Realized gains/(losses) Securities available-for-sale Corporate debt $ ( 11 ) $ — $ — Trading securities Corporate debt — — 89 Mutual funds held in rabbi trust ( 138 ) — — Total investments $ ( 149 ) $ — $ 89
Summary of Fair Value of Investments Based upon Contractual Maturities	The following table summarizes the fair value of the investments based upon the contractual maturities: Less than one year Due in 1 - 5 years Total (In thousands) 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 Mutual funds held in rabbi trust 10,485 — 10,485 Total $ 70,968 $ 63,893 $ 134,861 As of December 31, 2022 Trading securities U.S. Treasuries $ 24,618 $ 49,791 $ 74,409 Mutual funds held in rabbi trust 9,383 — 9,383 Total $ 34,001 $ 49,791 $ 83,792
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 as of December 31, 2023: 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, 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, 2023
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, 2023 December 31, 2022 Receivables from broker-dealers, clearing organizations and customers: (In thousands) Securities failed-to-deliver – broker-dealers and clearing organizations $ 282,125 $ 144,523 Securities failed-to-deliver – customers 284,322 235,056 Deposits with clearing organizations and broker-dealers 115,151 88,923 Other 6,338 7,833 Total $ 687,936 $ 476,335 Payables to broker-dealers, clearing organizations and customers: Securities failed-to-receive – broker-dealers and clearing organizations $ 125,022 $ 224,816 Securities failed-to-receive – customers 405,186 71,828 Other 7,190 7,349 Total $ 537,398 $ 303,993

Acquisitions and Equity Inves_2

Acquisitions and Equity Investments (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of changes in Goodwill and Intangible assets	The following is a summary of changes in goodwill and intangible assets for the year ended December 31, 2023: (In thousands) Balance at December 31, 2022 $ 154,789 Goodwill from Pragma Acquisition 81,917 Balance at December 31, 2023 $ 236,706
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, 2023 December 31, 2022 Cost Accumulated Net carrying Cost Accumulated Net carrying (In thousands) Customer relationships $ 140,348 $ ( 50,987 ) $ 89,361 $ 129,991 $ ( 34,310 ) $ 95,681 Technology and other intangibles 41,130 ( 11,383 ) 29,747 11,430 ( 9,046 ) 2,384 Total $ 181,478 $ ( 62,370 ) $ 119,108 $ 141,421 $ ( 43,356 ) $ 98,065

Capitalized Software, Furnitu_2

Capitalized Software, Furniture, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 2022 (In thousands) Software development costs $ 261,850 $ 218,848 Computer hardware and related software 42,913 37,614 Office hardware 7,609 8,455 Furniture and fixtures 6,508 6,952 Leasehold improvements 31,214 30,660 350,094 302,529 Accumulated depreciation and amortization ( 247,423 ) ( 202,273 ) Total $ 102,671 $ 100,256

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes	The provision for income taxes consists of the following: Year Ended December 31, 2023 2022 2021 (In thousands) Current: Federal $ 49,028 $ 52,865 $ 36,661 State and local 4,047 20,716 17,238 Foreign 27,385 21,030 19,018 Total current provision 80,460 94,611 72,917 Deferred: Federal ( 2,823 ) ( 5,830 ) 2,249 State and local ( 754 ) ( 1,350 ) 778 Foreign ( 2,238 ) 633 91 Total deferred provision ( 5,815 ) ( 6,547 ) 3,118 Provision for income taxes $ 74,645 $ 88,064 $ 76,035
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, 2023 2022 2021 U.S. federal statutory tax rate 21.0 % 21.0 % 21.0 % State and local taxes - net of federal benefit 0.8 4.6 4.4 Tax credits ( 1.0 ) ( 0.4 ) ( 0.4 ) Foreign rate differential benefit 0.9 ( 0.1 ) ( 0.2 ) Excess tax benefit from stock-based compensation 0.1 ( 0.1 ) ( 2.9 ) Other, net 0.6 1.0 0.9 Effective tax rate 22.4 % 26.0 % 22.8 %
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, 2023 2022 (In thousands) Deferred tax assets: Stock compensation expense $ 4,441 $ 3,451 Operating lease liabilities 17,128 17,842 Deferred Compensation 2,596 2,425 Other 1,015 1,774 Total deferred tax assets 25,180 25,492 Valuation allowance — — Net deferred tax assets 25,180 25,492 Deferred tax liabilities: Depreciation ( 8,617 ) ( 9,956 ) Capitalized software development costs — ( 3,923 ) Goodwill and intangible assets ( 3,987 ) ( 4,829 ) Operating lease right-of-use assets ( 13,507 ) ( 14,176 ) Other deferred tax liabilities ( 276 ) — Deferred tax (liability) asset, net $ ( 1,207 ) $ ( 7,392 )
Reconciliation of the Unrecognized Tax Benefits	A reconciliation of the unrecognized tax benefits is as follows: Year Ended December 31, 2023 2022 2021 (In thousands) Balance at beginning of year $ 9,835 $ 15,089 $ 16,317 Increase/(decrease) based on tax positions related to prior periods — 160 ( 1,228 ) (Decrease) related to settlements with taxing authorities ( 6,705 ) ( 5,414 ) — Balance at end of year $ 3,130 $ 9,835 $ 15,089

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2023
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: December 31, 2023 2023 2022 2021 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,648 37,919 38,005 Exercise of stock options 6 29 92 Issuance of restricted stock and performance shares, net of cancellations 97 66 48 Shares withheld for withholding tax payments ( 81 ) ( 86 ) ( 75 ) Repurchases — ( 280 ) ( 151 ) Reissuance of treasury stock 5 — — Treasury stock used for acquisition 225 — — Outstanding shares of voting common stock at the end of year 37,900 37,648 37,919

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation Expense	Total stock-based compensation expense was as follows: Year Ended December 31, 2023 2022 2021 (In thousands) Employees Restricted stock, restricted stock units, performance shares $ 24,205 $ 24,593 $ 23,041 Stock options 3,592 3,583 2,961 27,797 28,176 26,002 Non-employee directors Restricted stock and restricted stock units 1,393 1,688 1,312 Total stock-based compensation $ 29,190 $ 29,864 $ 27,314
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, excluding the two awards based on the Monte Carlo model discussed below: Year Ended December 31, 2023 2022 2021 Expected life (years) 5.0 5.0 5.0 Risk-free interest rate 3.6 % 1.5 % 0.4 % Expected volatility 35.8 % 32.6 % 31.2 % Expected dividend yield 0.8 % 0.7 % 0.4 %
Stock Option Activity	The following table reports stock option activity during the years ended December 31, 2023, 2022 and 2021 and the intrinsic value as of December 31, 2023, 2022 and 2021: Number Weighted-Average Exercise Price ($) Remaining Intrinsic Value ($) (In thousands) Outstanding at December 31, 2020 387,372 223.60 Granted 17,897 517.88 Canceled ( 616 ) 394.77 Exercised ( 91,900 ) 107.05 Outstanding at December 31, 2021 312,753 274.35 Granted 23,904 352.15 Canceled ( 1,646 ) 421.08 Exercised ( 28,758 ) 157.08 Outstanding at December 31, 2022 306,253 290.65 Granted 13,908 358.53 Canceled ( 551 ) 382.12 Exercised ( 5,653 ) 166.34 761 Outstanding at December 31, 2023 313,957 295.74 1.1 6,214 Exercisable at December 31, 2023 202,562 285.35 0.7 5,502
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, 2023, as well as the target and maximum share payouts for each award date granted: Award Date 2023 Estimate Target Maximum January 15, 2021 4,739 12,185 24,370 August 1, 2021 437 1,070 2,140 January 31, 2022 11,343 18,155 36,310 March 1, 2022 2,490 3,986 7,972 February 15, 2023 14,178 18,263 36,526
Restricted Stock, Restricted Stock Unit, Performance Share and Performance Stock Unit Activity	The following table reports restricted stock, restricted stock unit, performance share and performance stock unit activity during the years ended December 31, 2023, 2022 and 2021: Number of Restricted Shares Weighted-Average Grant Date Fair Value Outstanding at December 31, 2020 230,647 $ 224.63 Granted 47,142 Performance share pay-out — Canceled ( 3,911 ) Vested ( 111,268 ) 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

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023 2022 2021 (In thousands, except per share amounts) Basic weighted average shares outstanding 37,546 37,468 37,508 Dilutive effect of stock options and restricted stock 108 175 589 Diluted weighted average shares outstanding 37,654 37,643 38,097 Basic earnings per share $ 6.87 $ 6.68 $ 6.88 Diluted earnings per share 6.85 6.65 6.77

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
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, 2023, 2022 and 2021 : Year Ended December 31, Lease cost: Classification 2023 2022 2021 (In thousands) Operating lease cost - office space Occupancy $ 12,861 $ 13,015 $ 13,202 Operating lease cost for subleased/assigned properties Other, net — 469 2,054 Operating lease cost - equipment Technology and communications 98 — — Variable lease costs Occupancy 237 96 13 Sublease income Other, net — ( 405 ) ( 2,079 ) Net operating lease cost $ 13,196 $ 13,175 $ 13,190
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, 2023 December 31, 2022 Weighted average remaining lease term (in years) - operating leases 9.6 10.6 Weighted average discount rate - operating leases 6.0 % 5.9 % Weighted average remaining lease term (in years) - finance leases 1.8 — Weighted average discount rate - finance leases 7.2 % —
Schedule of Maturity of Lease Liabilities	The following table presents the maturity of lease liabilities as of December 31, 2023: Operating Leases Finance Leases (In thousands) 2024 $ 12,986 $ 117 2025 12,093 88 2026 11,521 — 2027 8,956 — 2028 8,602 — 2029 and thereafter 51,269 — Total lease payments 105,427 205 Less: imputed interest 25,750 13 Present value of lease liabilities $ 79,677 $ 192

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2023
Segment Reporting [Abstract]
Summary of Revenue and Long-lived Assets	Revenues for the years ended December 31, 2023, 2022 and 2021, and long-lived assets as of December 31, 2023 and 2022 were as follows: Year Ended December 31, 2023 2022 2021 (In thousands) Revenues Americas $ 597,145 $ 581,935 $ 568,918 Europe 136,989 119,112 110,068 Asia 18,413 17,253 19,965 Total $ 752,547 $ 718,300 $ 698,951 As of December 31, 2023 December 31, 2022 (In thousands) Long-lived assets, as defined Americas $ 87,513 $ 82,008 Europe 14,717 17,723 Asia 441 525 Total $ 102,671 $ 100,256

Cash and Cash Equivalents and_2

Cash and Cash Equivalents and Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2023
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 2023 2022 2021 (In thousands) Cash and cash equivalents Cash and cash equivalents $ 451,280 $ 430,746 $ 506,735 Cash segregated for regulatory Cash segregated under federal 45,122 50,947 50,159 Deposits with clearing organizations Receivables from broker-dealers, 115,151 88,923 68,565 Other deposits Prepaid expenses and other assets 119 2,048 108 Total $ 611,672 $ 572,664 $ 625,567

Parent Company Information (Tab

Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2023
Condensed Financial Information Disclosure [Abstract]
Condensed Statements of Financial Condition	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Financial Condition As of December 31, 2023 December 31, 2022 (In thousands) ASSETS Cash and cash equivalents $ 65,951 $ 43,909 Investments, at fair value 30,225 5,343 Accounts receivable 1,923 769 Receivable from subsidiaries 18,010 8,962 Intangible assets, net of accumulated amortization 21 23 Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization 17,644 19,557 Operating lease right-of-use assets 55,113 57,402 Investments in subsidiaries 1,140,798 985,222 Prepaid expenses and other assets 45,140 41,511 Income and other tax receivable 7,674 11,474 Total assets $ 1,382,499 $ 1,174,172 LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities Accrued employee compensation 8,589 $ 9,693 Income and other tax liabilities 3,000 12 Accounts payable, accrued expenses and other liabilities 8,212 11,087 Operating lease liabilities 69,735 72,287 Total liabilities 89,536 93,079 Stockholders' equity Preferred stock — — Series A Preferred Stock — — Common stock voting 123 123 Common stock non-voting — — Additional paid-in capital 333,292 345,468 Treasury stock ( 260,298 ) ( 328,326 ) Retained earnings 1,244,216 1,101,525 Accumulated other comprehensive loss ( 24,370 ) ( 37,697 ) Total stockholders' equity 1,292,963 1,081,093 Total liabilities and stockholders' equity $ 1,382,499 $ 1,174,172
Condensed Statements of Operations	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations Year Ended December 31, 2023 2022 2021 (In thousands) Revenues $ 270,700 $ 257,200 $ 173,000 Expenses Employee compensation and benefits 13,938 17,655 17,887 Depreciation and amortization 2,153 2,136 2,123 Professional and consulting fees 5,828 5,528 7,081 General and administrative 2,301 3,081 3,620 Total expenses 24,220 28,400 30,711 Operating income 246,480 228,800 142,289 Other income (expense) Interest income 3,557 272 132 Interest expense ( 155 ) ( 271 ) — Equity in earnings of unconsolidated affiliate 735 1,126 — Other, net ( 369 ) ( 2,633 ) ( 2,950 ) Total other income (expense) 3,768 ( 1,506 ) ( 2,818 ) Income before income taxes and equity in undistributed earnings of subsidiaries 250,248 227,294 139,471 Benefit from income taxes ( 5,586 ) ( 7,710 ) ( 6,472 ) Income before equity in undistributed income of subsidiaries 255,834 235,004 145,943 Equity in undistributed income of subsidiaries 2,221 15,220 111,945 Net income 258,055 250,224 257,888 Other comprehensive income (loss), net 13,327 ( 24,367 ) ( 8,680 ) Comprehensive income $ 271,382 $ 225,857 $ 249,208
Condensed Statements of Cash Flows	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2023 2022 2021 (In thousands) Cash flows from operating activities Net income $ 258,055 $ 250,224 $ 257,888 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 2,153 2,136 2,123 Amortization of operating lease right-of-use assets 3,361 3,347 4,484 Stock-based compensation expense 9,725 12,554 12,706 Deferred taxes 101 ( 5,076 ) 1,712 Equity in undistributed income of subsidiaries ( 2,221 ) ( 15,220 ) ( 111,945 ) Other ( 4,675 ) 441 — Changes in operating assets and liabilities: (Increase)/decrease in accounts receivable ( 1,154 ) ( 769 ) 178 Decrease in receivable from subsidiaries 5,474 7,931 47,371 Decrease/(increase) in prepaid expenses and other assets 1,296 ( 1,175 ) ( 219 ) (Increase)/decrease in mutual funds held in rabbi trust ( 189 ) 984 ( 1,516 ) (Decrease)/increase in accrued employee compensation ( 1,104 ) ( 1,372 ) 824 (Increase)/decrease in income and other tax receivables 3,800 ( 9,711 ) 7,265 Increase/(decrease) increase in income and other tax liabilities 2,287 62 ( 143 ) (Decrease)/increase in accounts payable, accrued expenses and other liabilities ( 861 ) 443 ( 607 ) (Decrease) in operating lease liabilities ( 3,624 ) ( 3,689 ) ( 4,673 ) Net cash provided by operating activities 272,424 241,110 215,449 Cash flows from investing activities Acquisition of business, net of cash and cash equivalents acquired ( 81,161 ) — ( 17,079 ) Acquisition of equity method investment — ( 34,400 ) — Investments in subsidiaries ( 10,058 ) ( 8,326 ) — Available-for-sale investments Proceeds from maturities and sales 4,454 — — Purchases ( 28,818 ) — — Purchases of furniture, equipment and leasehold improvements ( 239 ) ( 96 ) ( 198 ) Net cash (used in) investing activities ( 115,822 ) ( 42,822 ) ( 17,277 ) Cash flows from financing activities Cash dividend on common stock ( 109,658 ) ( 105,942 ) ( 99,791 ) Exercise of stock options 940 672 7,096 Withholding tax payments on restricted stock vesting and stock option exercises ( 25,839 ) ( 23,404 ) ( 33,890 ) Repurchases of common stock — ( 87,540 ) ( 63,189 ) Proceeds from short-term borrowings 100,000 100,000 — Repayments of short-term borrowings ( 100,000 ) ( 100,000 ) — Net cash (used in) financing activities ( 134,557 ) ( 216,214 ) ( 189,774 ) Effect of exchange rate changes on investments ( 3 ) 15 ( 2,324 ) Cash and cash equivalents including restricted cash Net increase (decrease) for the period 22,042 ( 17,911 ) 6,073 Beginning of period 43,909 61,820 55,747 End of period $ 65,951 $ 43,909 $ 61,820 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows (Continued) Year Ended December 31, 2023 2022 2021 (In thousands) Supplemental cash flow information: Cash paid for income taxes $ 55,784 $ 65,764 $ 41,103 Cash paid for interest 35 271 — Non-cash investing and financing activity: Exercise of stock options - cashless $ — $ 3,845 $ 2,750 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, 2023 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	2,000

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Revenue	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Significant Accounting Policies [Line Items]
Allowance for credit losses	$ 577	$ 590
Provision for bad debts	400	600	$ 200
Write-offs and other charges against the allowance for credit losses	$ 300	$ 100	$ 100
Number of revenue streams | Revenue	4
Settlement days of bond transaction	within one to two trading days
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Significant Accounting Policies [Line Items]
Aggregate amount of transaction price allocated to remaining performance obligations	$ 67,100
Expected time to recognize revenue for remaining performance obligation	58 months
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
ASU 2018-15 [Member]
Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Retrospective Application Impracticable [true false]	false
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
ASU 2017-04 [Member]
Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Retrospective Application Impracticable [true false]	false
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
ASU 2016-13 [Member]
Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Retrospective Application Impracticable [true false]	false
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true

Significant Accounting Polici_5

Significant Accounting Policies - Summary of Commission Revenue by Fee Type (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Commission revenue by fee type
Revenues	$ 752,547	$ 718,300	$ 698,951
Commissions [Member]
Commission revenue by fee type
Disclosed trading	323,038	321,603	333,712
Matched principal trading	178,517	175,440	155,465
Other Variable Transaction	4,979
Total variable transaction fees	521,756	514,021	501,577
Distribution fees and unused minimum fees	141,208	127,162	119,431
Revenues	662,964	641,183	621,008
Commissions [Member] | US Government Bonds [Member]
Commission revenue by fee type
Matched principal trading	$ 15,222	$ 16,978	$ 12,400

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Significant Accounting Policies [Line Items]
Revenues	$ 752,547	$ 718,300	$ 698,951
Information Services [Member]
Significant Accounting Policies [Line Items]
Revenues	46,383	39,314	38,175
Information Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	45,102	38,452	37,341
Information Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 1,281	$ 862	$ 834

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Significant Accounting Policies [Line Items]
Revenues	$ 752,547	$ 718,300	$ 698,951
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Revenues	40,178	36,877	38,922
Post-trade Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	40,061	36,835	38,850
Post-trade Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 117	$ 42	$ 72

Significant Accounting Polici_8

Significant Accounting Policies - Summary of Revenue Recognized from Contract Liabilities and Remaining Balance (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	$ 3,990
Payments received in advance of services to be performed	35,831
Revenue recognized for services performed during the period	(35,894)
Foreign Currency Translation	45
Deferred revenues, ending balance	4,539
Information Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	3,121
Payments received in advance of services to be performed	12,715
Revenue recognized for services performed during the period	(12,787)
Deferred revenues, ending balance	3,049
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	869
Payments received in advance of services to be performed	23,116
Revenue recognized for services performed during the period	(23,107)
Foreign Currency Translation	45
Deferred revenues, ending balance	923
Technology Services [Member]
Significant Accounting Policies [Line Items]
Payments received in advance of services to be performed	1,085
Revenue recognized for services performed during the period	(518)
Deferred revenues, ending balance	$ 567

Significant Accounting Polici_9

Significant Accounting Policies - Additional Information (Detail 1) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01 $ in Millions	Dec. 31, 2023 USD ($)
Significant Accounting Policies [Line Items]
Aggregate amount of transaction price allocated to remaining performance obligations	$ 67.1
Expected time to recognize revenue for remaining performance obligation	58 months

Regulatory Capital Requiremen_2

Regulatory Capital Requirements - Additional Information (Detail) $ in Millions	Dec. 31, 2023 USD ($)
Brokers And Dealers [Line Items]
Securities reserve deposit	$ 45.1
U.S. Subsidiaries
Brokers And Dealers [Line Items]
Aggregate net capital and financial resources in excess of required level	605.4
Aggregate net capital and financial resources, minimum capital requirement	36.1
U.S. Broker-Dealer Subsidiaries
Brokers And Dealers [Line Items]
Aggregate net capital and financial resources in excess of required level	306.3
Aggregate net capital and financial resources, minimum capital requirement	$ 9.3

Fair Value Measurements - Valua

Fair Value Measurements - Valuation of Company's Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets
Money market funds	$ 18,634	$ 59,173
Assets Fair Value Total	155,396	142,965
Liabilities
Contingent consideration payable	0	12,340
Total liabilities		14,028
Mutual Funds Held In Rabbi Trust [Member]
Assets
Trading securities, Fair value	10,485	9,383
U.S. Treasuries [Member]
Assets
Trading securities, Fair value	99,682	74,409
Foreign Currency Forward Position [Member]
Assets
Foreign currency forward position	1,901
Liabilities
Foreign currency forward position		1,688
Corporate Debt [Member]
Assets
Securities available-for-sale	24,694
Trading securities, Fair value	24,694
Level 1 [Member]
Assets
Money market funds	18,634	59,173
Assets Fair Value Total	18,634	59,173
Level 2 [Member]
Assets
Assets Fair Value Total	136,762	83,792
Liabilities
Total liabilities		1,688
Level 2 [Member] | Mutual Funds Held In Rabbi Trust [Member]
Assets
Trading securities, Fair value	10,485	9,383
Level 2 [Member] | U.S. Treasuries [Member]
Assets
Trading securities, Fair value	99,682	74,409
Level 2 [Member] | Foreign Currency Forward Position [Member]
Assets
Foreign currency forward position	1,901
Liabilities
Foreign currency forward position		1,688
Level 2 [Member] | Corporate Debt [Member]
Assets
Securities available-for-sale	$ 24,694
Level 3 [Member]
Liabilities
Contingent consideration payable		12,340
Total liabilities		$ 12,340

Fair Value Measurements - Summa

Fair Value Measurements - Summary of the Change in the Company's Contingent Consideration Payable (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Contingent consideration payable	$ 0	$ 12,340
Payments	(12,500)
Realized (Gain)/Loss	$ 160

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, 2023	Dec. 31, 2022
Financial assets not measured at fair value:
Financial assets not measured at fair value	$ 155,396	$ 142,965
Level 1 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	18,634	59,173
Level 2 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	136,762	83,792
Financial Assets and Liabilities not Measured [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	1,255,543	977,305
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	537,398	303,993
Financial Assets and Liabilities not Measured [Member] | Cash [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	432,646	371,573
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	45,122	50,947
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	89,839	78,450
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	687,936	476,335
Financial Assets and Liabilities not Measured [Member] | Level 1 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	592,919	511,443
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	432,646	371,573
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	45,122	50,947
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	115,151	88,923
Financial Assets and Liabilities not Measured [Member] | Level 2 [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	662,624	465,862
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	537,398	303,993
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	89,839	78,450
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	572,785	387,412
Financial Assets and Liabilities not Measured [Member] | Carrying Value [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	1,255,543	977,305
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	537,398	303,993
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	432,646	371,573
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	45,122	50,947
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	89,839	78,450
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	687,936	476,335
Financial Assets and Liabilities not Measured [Member] | Fair Value [Member]
Financial assets not measured at fair value:
Financial assets not measured at fair value	1,255,543	977,305
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	537,398	303,993
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	432,646	371,573
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	45,122	50,947
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	89,839	78,450
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	$ 687,936	$ 476,335

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
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
Proceeds from the sales and maturities of securities available-for-sale	29,500,000	0	$ 19,400,000
Purchases of investments	78,600,000	50,100,000	$ 25,000,000
Realized loss	1,500,000
Realized gain		800,000
Net unrealized gain/loss	3,600,000	(1,700,000)
Credit losses on available-for-sale securities	$ 0	$ 0

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Foreign Currency Forward Contracts (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Derivatives Fair Value [Line Items]
Notional value	$ 61,858	$ 62,160
Fair value of notional	63,759	60,472
Fair value of the asset/(liability)	$ 1,901	$ (1,688)

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Company's Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Investments, Amortized cost	$ 134,903	$ 86,417
Investments, Gross unrealized gains	673
Investments, Gross unrealized losses	(715)	(2,625)
Investments, at fair value	134,861	83,792
Corporate Debt [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	24,705
Trading securities, Gross unrealized gains	55
Trading securities, Gross unrealized losses	(66)
Trading securities, Fair value	24,694
Investments, at fair value	24,694
U.S. Treasuries [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	99,236	74,943
Trading securities, Gross unrealized gains	446
Trading securities, Gross unrealized losses		(534)
Trading securities, Fair value	99,682	74,409
Investments, at fair value	99,682	74,409
Mutual Funds Held In Rabbi Trust [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	10,962	11,474
Trading securities, Gross unrealized gains	172
Trading securities, Gross unrealized losses	(649)	(2,091)
Trading securities, Fair value	10,485	9,383
Investments, at fair value	$ 10,485	$ 9,383

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	$ 1,719	$ (2,625)	$ 1,143
Realized gains/(losses)	(149)		89
Corporate Debt [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	(11)
Realized gains/(losses)	(11)		89
U.S. Treasuries [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	446	(534)	(111)
Mutual Funds Held In Rabbi Trust [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	1,284	$ (2,091)	1,254
Realized gains/(losses)	$ (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, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Less than one year	$ 70,968	$ 34,001
Due in 1 - 5 years	63,893	49,791
Total	134,861	83,792
U.S. Treasuries [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than one year	49,756	24,618
Due in 1 - 5 years	49,926	49,791
Total	99,682	74,409
Mutual Funds Held In Rabbi Trust [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than one year	10,485	9,383
Total	10,485	$ 9,383
Corporate Debt [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than one year	10,727
Due in 1 - 5 years	13,967
Total	$ 24,694

Fair Value Measurements - Sum_6

Fair Value Measurements - Summary of Fair Values and Unrealized Losses on Investments (Detail) - Corporate Debt [Member] $ in Thousands	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than Twelve Months, Estimated Fair value	$ 17,658
Less than Twelve Months, Gross unrealized losses	(66)
Twelve Months or More, Gross unrealized losses	0
Twelve Months or More, Gross unrealized losses	0
Estimated Fair value, Total	17,658
Gross unrealized losses, Total	$ (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, 2023	Dec. 31, 2022
Receivables from broker-dealers, clearing organizations and customers:
Securities failed-to-deliver - broker-dealers and clearing organizations	$ 282,125	$ 144,523
Securities failed-to-deliver - customers	284,322	235,056
Deposits with clearing organizations and broker-dealers	115,151	88,923
Other	6,338	7,833
Total	687,936	476,335
Payables to broker-dealers, clearing organizations and customers:
Securities failed-to-receive - broker-dealers and clearing organizations	125,022	224,816
Securities failed-to-receive - customers	405,186	71,828
Other	7,190	7,349
Total	$ 537,398	$ 303,993

Acquisitions and Equity Inves_3

Acquisitions and Equity Investments - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Oct. 02, 2023	Dec. 31, 2023	Dec. 31, 2022	May 01, 2023	May 01, 2022	Apr. 09, 2021
Business Acquisition [Line Items]
Contingent consideration payable		$ 0
Goodwill		236,706	$ 154,789
Contingent consideration paid		0	12,340
Accounts Payable, Accrued Expenses and Other Liabilities [Member]
Business Acquisition [Line Items]
Contingent consideration payable						$ 22,500
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		700	$ 1,100
Reimbursable support costs for equity method investee		1,100
RFQ Hub Holdings LLC [Member] | Prepaid Expenses And Other Assets [Member]
Business Acquisition [Line Items]
Recorded investments		$ 36,300
Muni Brokers L L C [Member]
Business Acquisition [Line Items]
Contingent consideration paid				$ 12,500	$ 8,300

Acquisitions and Equity Inves_4

Acquisitions and Equity Investments - Summary of Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Oct. 02, 2023	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Goodwill		$ 236,706	$ 154,789
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Line Items]
Amortization expense associated with identifiable intangible assets	$ 18.6	$ 16.4	$ 13.4
Estimated total amortization expense 2024	19.9
Estimated total amortization expense 2025	17
Estimated total amortization expense 2026	15.3
Estimated total amortization expense 2027	13.9
Estimated total amortization expense 2028	12.3
Indefinite-lived Intangible Assets [Member]
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 236.7	$ 154.8

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Changes in Goodwill and Intangible assets (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Beginning Balance	$ 154,789
Goodwill from Pragma Acquisition	81,917
Goodwill, Ending Balance	$ 236,706

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Summary of Company's Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Finite Lived Intangible Assets [Line Items]
Costs	$ 181,478	$ 141,421
Accumulated amortization	(62,370)	(43,356)
Net carrying amount	119,108	98,065
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Costs	140,348	129,991
Accumulated amortization	(50,987)	(34,310)
Net carrying amount	89,361	95,681
Technology and Other Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Costs	41,130	11,430
Accumulated amortization	(11,383)	(9,046)
Net carrying amount	$ 29,747	$ 2,384

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, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 350,094	$ 302,529
Accumulated depreciation and amortization	(247,423)	(202,273)
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	102,671	100,256
Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	261,850	218,848
Computer Hardware and Related Software [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	42,913	37,614
Office Hardware [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	7,609	8,455
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	6,508	6,952
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 31,214	$ 30,660

Capitalized Software, Furnitu_4

Capitalized Software, Furniture, Equipment and Leasehold Improvements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Software development costs	$ 43.1	$ 38.7

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
Federal	$ 49,028	$ 52,865	$ 36,661
State and local	4,047	20,716	17,238
Foreign	27,385	21,030	19,018
Total current provision	80,460	94,611	72,917
Deferred:
Federal	(2,823)	(5,830)	2,249
State and local	(754)	(1,350)	778
Foreign	(2,238)	633	91
Total deferred provision	(5,815)	(6,547)	3,118
Provision for income taxes	$ 74,645	$ 88,064	$ 76,035

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from U.S. operations	$ 228,800	$ 236,400	$ 234,600
Pre-tax income from foreign operations	$ 103,900	$ 101,900	$ 99,300
U.S. federal statutory tax rate	21%	21%	21%
Provision for income taxes	$ 74,645	$ 88,064	$ 76,035
Unrecognized tax benefits	3,130	9,835	15,089	$ 16,317
Recognized penalties and interest on unrecognized tax benefits	1,600	5,800	$ 3,300
Penalties and interest accrued on unrecognized tax benefits	$ 2,600	$ 7,900
New York State [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2015
New York State [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2017
New York City [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2016
New York City [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	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, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
U.S. federal statutory tax rate	21%	21%	21%
State and local taxes - net of federal benefit	0.80%	4.60%	4.40%
Tax credits	(1.00%)	(0.40%)	(0.40%)
Foreign rate differential benefit	0.90%	(0.10%)	(0.20%)
Excess tax benefit from stock-based compensation	0.10%	(0.10%)	(2.90%)
Other, net	0.60%	1%	0.90%
Effective tax rate	22.40%	26%	22.80%

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Stock compensation expense	$ 4,441	$ 3,451
Operating lease liabilities	17,128	17,842
Deferred Compensation	2,596	2,425
Other	1,015	1,774
Total deferred tax assets	25,180	25,492
Valuation allowance	0
Net deferred tax assets	25,180	25,492
Deferred tax liabilities:
Depreciation	(8,617)	(9,956)
Capitalized software development costs	0	(3,923)
Goodwill and intangible assets	(3,987)	(4,829)
Operating lease right-of-use assets	(13,507)	(14,176)
Other deferred tax liabilities	(276)	0
Deferred tax (liability) asset, net	$ (1,207)	$ (7,392)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 9,835	$ 15,089	$ 16,317
Increase/(decrease) based on tax positions related to prior periods	0	160	(1,228)
(Decrease) related to cash settlements with taxing authorities	(6,705)	(5,414)
Balance at end of year	$ 3,130	$ 9,835	$ 15,089

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended			12 Months Ended
	Jan. 31, 2021	Jan. 31, 2019	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 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
Shares repurchase program authorized									$ 150,000,000
Cash dividends declared per common share			$ 0.72	$ 0.7	$ 0.66	$ 2.88	$ 2.8	$ 2.64
Share Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase program period		2 years
Shares repurchase program authorized	$ 100,000,000	$ 100,000,000
Share repurchase program, commencement date		2019-04
Share repurchase program, commencement date	Apr. 30, 2021
Stock repurchase program, expiration Date		Mar. 31, 2021
Share repurchase program, completion date	Jan. 31, 2022
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,648,148
Exercise of stock options	5,653	28,758	91,900
Outstanding shares of voting common stock at the end of year	37,899,688	37,648,148
Voting Common Stock [Member]
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,648,000	37,919,000	38,005,000
Exercise of stock options	6,000	29,000	92,000
Issuance of restricted stock and performance shares, net of cancellations	97,000	66,000	48,000
Shares withheld for withholding tax payments	(81,000)	(86,000)	(75,000)
Repurchases	0	(280,000)	(151,000)
Reissuance of treasury stock	5	0	0
Treasury stock used for acquisition	225	0	0
Outstanding shares of voting common stock at the end of year	37,900,000	37,648,000	37,919,000

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended					12 Months Ended
	Apr. 30, 2023	Mar. 31, 2022	Aug. 31, 2021	Jan. 31, 2019	Nov. 30, 2018	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jun. 08, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under the stock incentive plan						2,436,113
Period vested for option grants							5 years
Weighted-average fair value option granted						$ 123.47	$ 101.38	$ 137.66
Number of awards excluded from option-pricing model						2
Grant date fair value						$ 761
Fair value assumptions, Dividend yield rate						0.80%	0.70%	0.40%
Closing price of common stock						$ 292.85
Unrecognized compensation costs related to non-vested						$ 2,200
Weighted-average period over which cost is expected to be recognized						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						$ 5,502
Common stock, shares issued						40,940,769	40,918,660
Employee Stock Option | President and Chief Operating Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock option equity instruments granted during the period				76,868	148,524
Restricted Stock Restricted Stock Units Performance Shares And Performance Stock Unit [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested						$ 38,400
Weighted-average period over which cost is expected to be recognized						1 year 6 months
Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Pay-out ranges, Maximum						200%	0%
Performance Percentage to Metrics Performance Equity Awards						0.389
Number of non-option equity instruments granted during the period	5,039	3,986	1,070
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
Number of non-option equity instruments granted during the period				18,914	37,742
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						116,566			121,221
Common stock, shares issued						4,655
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants						3 years
Options Expiration Period						6 years
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants						5 years
Options Expiration Period						10 years

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restricted Stock, Restricted Stock Units, Performance Shares and Performance Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 24,205	$ 24,593	$ 23,041
Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	27,797	28,176	26,002
Employees [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	3,592	3,583	2,961
Employees [Member] | Restricted Stock and Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	1,393	1,688	1,312
Non-Employee Directors [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 29,190	$ 29,864	$ 27,314

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Expected life (years)	5 years	5 years	5 years
Risk-free interest rate	3.60%	1.50%	0.40%
Expected volatility	35.80%	32.60%	31.20%
Expected dividend yield	0.80%	0.70%	0.40%

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Number of Shares, Beginning balance	306,253	312,753	387,372
Number of Shares, Granted	13,908	23,904	17,897
Number of Shares, Canceled	(551)	(1,646)	(616)
Number of Shares, Exercised	(5,653)	(28,758)	(91,900)
Number of Shares, Ending Balance	313,957	306,253	312,753
Number of Shares, Exercisable	202,562
Weighted Average Exercise Price, Beginning Balance	$ 290.65	$ 274.35	$ 223.6
Weighted Average Exercise Price, Granted	358.53	352.15	517.88
Weighted Average Exercise Price, Canceled	382.12	421.08	394.77
Weighted Average Exercise Price, Exercised	166.34	157.08	107.05
Weighted Average Exercise Price, Ending Balance	295.74	$ 290.65	$ 274.35
Weighted Average Exercise Price, Exercisable	$ 285.35
Remaining Contractual Term, Outstanding at December 31, 2023	1 year 1 month 6 days
Remaining Contractual Term, Exercisable at December 31, 2023	8 months 12 days
Intrinsic Value, Exercised	$ 761
Intrinsic Value, Ending Balance	6,214
Intrinsic Value, Exercisable	$ 5,502

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Schedule of Estimated, Target and Maximum Share Payouts (Details)	Dec. 31, 2023 shares
January 15, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Jan. 15, 2021
2023 Estimate	4,739
Target	12,185
Maximum	24,370
August 1, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Aug. 01, 2021
2023 Estimate	437
Target	1,070
Maximum	2,140
January 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Jan. 31, 2022
2023 Estimate	11,343
Target	18,155
Maximum	36,310
March 1, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award Date	Mar. 01, 2022
2023 Estimate	2,490
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
2023 Estimate	14,178
Target	18,263
Maximum	36,526

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Restricted Stock, Restricted Stock Unit, Performance Share and Performance Stock Unit Activity (Detail) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Shares, Beginning balance	162,356	162,610	230,647
Number of Restricted Shares, Granted	90,242	72,861	47,142
Number of Restricted Shares, Performance share pay-out	12,145	0	0
Number of Restricted Shares, Canceled	(5,272)	(8,513)	(3,911)
Number of Restricted Shares, Vested	(98,927)	(64,602)	(111,268)
Number of Restricted Shares, Ending balance	160,544	162,356	162,610
Weighted Average Grant Date Fair Value, Beginning balance	$ 321.04	$ 316.56	$ 224.63
Weighted Average Grant Date Fair Value, Ending balance	$ 346.15	$ 321.04	$ 316.56

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Basic weighted average shares outstanding	37,546	37,468	37,508
Dilutive effect of stock options and restricted stock	108	175	589
Diluted weighted average shares outstanding	37,654	37,643	38,097
Basic earnings per share	$ 6.87	$ 6.68	$ 6.88
Diluted earnings per share	$ 6.85	$ 6.65	$ 6.77

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock Options and Restricted Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options and restricted stock excluded from the computation of diluted earnings per share	306,678	310,447	41,240

Credit Agreements and Short-t_2

Credit Agreements and Short-term Financing - Additional Information (Detail) - USD ($)			12 Months Ended
	Aug. 09, 2023	Oct. 15, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Line Of Credit Facility [Line Items]
Interest expense on borrowings			$ 100,000	$ 0	$ 100,000
Interest expense on short-term debt			700,000	400,000	800,000
Outstanding overdrafts payable			0
Collateralized Agreements [Member]
Line Of Credit Facility [Line Items]
Maximum available borrowings to subsidiary under agreement			500,000,000
Outstanding borrowings under agreement			0
Unused borrowing capacity, amount under agreement			$ 500,000,000
Collateralized Agreements [Member] | Base Rate [Member]
Line Of Credit Facility [Line Items]
Interest rate, stated percentage			1%
2021 Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Revolving loans and letters of credit		$ 500,000,000
Expiration period of credit agreement		Oct. 15, 2024
Period of credit agreement		3 years
Sub-limit for letter of credit		$ 5,000,000
Sub-limit for swingline loans		$ 50,000,000
Interest expense on borrowings			$ 100,000	$ 300,000	$ 0
Line of Credit Facility, Description			On October 15, 2021, the Company entered into a three-year revolving credit facility (the “2021 Credit Agreement”) provided by a syndicate of lenders and JPMorgan Chase Bank, N.A., as administrative agent
2023 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			$ 100,000
Line of Credit Facility, Description			On August 9, 2023, the Company replaced the 2021 Credit Agreement with a new three-year revolving credit facility (the “2023 Credit Agreement”) provided by a syndicate of lenders and JPMorgan Chase Bank, N.A., as administrative agent
Revolving Credit Facility [Member] | 2023 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] | 2023 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 Thousands	12 Months Ended
	Dec. 31, 2023 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	$ 192
Finance lease expense	$ 100
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Lease Cost [Line Items]
Net operating lease cost	$ 13,196	$ 13,175	$ 13,190
Finance lease cost - interest	100
Other, net [Member]
Lease Cost [Line Items]
Operating lease cost for subleased/assigned properties	0	469	2,054
Sublease income	0	(405)	(2,079)
Occupancy [Member]
Lease Cost [Line Items]
Operating lease cost - office space	12,861	13,015	13,202
Variable lease costs	237	96	13
Technology and Communications [Member]
Lease Cost [Line Items]
Operating lease cost - equipment	$ 98	$ 0	$ 0

Leases - Summary of Weighted Av

Leases - Summary of Weighted Average Remaining Lease Term and Discount Rate (Details)	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Weighted average remaining lease term (in years) - operating leases	9 years 7 months 6 days	10 years 7 months 6 days
Weighted average discount rate - operating leases	6%	5.90%
Weighted average remaining lease term (in years) - finance leases	1 year 9 months 18 days	0 years
Weighted average discount rate - finance leases	7.20%	0%

Leases - Schedule of Maturity o

Leases - Schedule of Maturity of Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
2024	$ 12,986
2025	12,093
2026	11,521
2027	8,956
2028	8,602
2029 and thereafter	51,269
Total lease payments	105,427
Less: imputed interest	25,750
Present value of lease liabilities	79,677	$ 82,676
2024	117
2025	88
2026	0
2027	0
2028	0
2029 and thereafter	0
Total lease payments	205
Less: imputed interest	13
Present value of lease liabilities	$ 192
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Liabilities

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2023
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)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 752,547	$ 718,300	$ 698,951
Long-lived assets	102,671	100,256
Americas [Member]
Segment Reporting Information [Line Items]
Revenues	597,145	581,935	568,918
Long-lived assets	87,513	82,008
Europe [Member]
Segment Reporting Information [Line Items]
Revenues	136,989	119,112	110,068
Long-lived assets	14,717	17,723
Asia [Member]
Segment Reporting Information [Line Items]
Revenues	18,413	17,253	$ 19,965
Long-lived assets	$ 441	$ 525

Retirement and Deferred Compe_2

Retirement and Deferred Compensation Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Contribution to defined plans	$ 7.6	$ 6.1	$ 5.8
Non-qualified deferred cash incentive plan maximum eligibility percentage of employees	100%
Mutual fund investments and deferred compensation obligation, at fair value	$ 10.5	$ 9.4

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, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 451,280	$ 430,746
Cash segregated under federal regulations	45,122	50,947
Deposits with clearing organizations and broker-dealers	115,151	88,923
Total	611,672	572,664	$ 625,567
Cash and Cash Equivalents [Member]
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	451,280	430,746	506,735
Cash Segregated under Federal Regulations [Member]
Cash And Cash Equivalents [Line Items]
Cash segregated under federal regulations	45,122	50,947	50,159
Receivables from Broker-Dealers, Clearing Organizations and Customers [Member]
Cash And Cash Equivalents [Line Items]
Deposits with clearing organizations and broker-dealers	115,151	88,923	68,565
Prepaid Expenses and Other Assets [Member]
Cash And Cash Equivalents [Line Items]
Other deposits	$ 119	$ 2,048	$ 108

Parent Company Information - Co

Parent Company Information - Condensed Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 451,280	$ 430,746
Investments, at fair value	134,861	83,792
Accounts receivable	89,839	78,450
Intangible assets, net of accumulated amortization	119,108	98,065
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	102,671	100,256
Operating lease right-of-use assets	63,045	66,106
Prepaid expenses and other assets	84,499	68,289
Total assets	2,015,067	1,607,775
Liabilities
Accrued employee compensation	60,124	56,302
Income and other tax liabilities	7,892	28,448
Accounts payable, accrued expenses and other liabilities	37,013	55,263
Operating lease liabilities	79,677	82,676
Total liabilities	722,104	526,682
Stockholders' equity
Preferred stock	0	0
Common stock voting	123	123
Additional paid-in capital	333,292	345,468
Treasury stock	260,298	328,326
Retained earnings	1,244,216	1,101,525
Accumulated other comprehensive loss	(24,370)	(37,697)
Total stockholders' equity	1,292,963	1,081,093	$ 1,041,309	$ 955,061
Total liabilities and stockholders' equity	2,015,067	1,607,775
MarketAxess Holdings Inc. (Parent) [Member]
ASSETS
Cash and cash equivalents	65,951	43,909
Investments, at fair value	30,225	5,343
Accounts receivable	1,923	769
Receivable from subsidiaries	18,010	8,962
Intangible assets, net of accumulated amortization	21	23
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	17,644	19,557
Operating lease right-of-use assets	55,113	57,402
Investments in subsidiaries	1,140,798	985,222
Prepaid expenses and other assets	45,140	41,511
Income and other tax receivable	7,674	11,474
Total assets	1,382,499	1,174,172
Liabilities
Accrued employee compensation	8,589	9,693
Income and other tax liabilities	3,000	12
Accounts payable, accrued expenses and other liabilities	8,212	11,087
Operating lease liabilities	69,735	72,287
Total liabilities	89,536	93,079
Stockholders' equity
Preferred stock	0	0
Common stock voting	123	123
Additional paid-in capital	333,292	345,468
Treasury stock	(260,298)	(328,326)
Retained earnings	1,244,216	1,101,525
Accumulated other comprehensive loss	(24,370)	(37,697)
Total stockholders' equity	1,292,963	1,081,093
Total liabilities and stockholders' equity	1,382,499	1,174,172
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, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues	$ 752,547	$ 718,300	$ 698,951
Expenses
Employee compensation and benefits	206,926	182,104	170,916
Depreciation and amortization	70,557	61,446	53,447
Technology and communications	62,801	52,964	42,474
Professional and consulting fees	31,935	33,949	41,925
Occupancy	14,216	14,121	13,320
General and administrative	23,042	19,200	14,501
Total expenses	437,528	391,424	361,716
Operating income	315,019	326,876	337,235
Other income (expense)
Interest income	22,425	5,040	401
Interest expense	(1,983)	(700)	(842)
Equity in earnings of unconsolidated affiliate	735	1,126	0
Other, net	(3,496)	5,946	(2,871)
Total other income (expense)	17,681	11,412	(3,312)
Benefit from income taxes	74,645	88,064	76,035
Net income	258,055	250,224	257,888
Comprehensive income	271,382	225,857	249,208
MarketAxess Holdings Inc. (Parent) [Member]
Revenues	270,700	257,200	173,000
Expenses
Employee compensation and benefits	13,938	17,655	17,887
Depreciation and amortization	2,153	2,136	2,123
Professional and consulting fees	5,828	5,528	7,081
General and administrative	2,301	3,081	3,620
Total expenses	24,220	28,400	30,711
Operating income	246,480	228,800	142,289
Other income (expense)
Interest income	3,557	272	132
Interest expense	(155)	(271)	0
Equity in earnings of unconsolidated affiliate	735	1,126	0
Other, net	(369)	(2,633)	(2,950)
Total other income (expense)	3,768	(1,506)	(2,818)
Income before income taxes and equity in undistributed earnings of subsidiaries	250,248	227,294	139,471
Benefit from income taxes	(5,586)	(7,710)	(6,472)
Income before equity in undistributed income of subsidiaries	255,834	235,004	145,943
Equity in undistributed income of subsidiaries	2,221	15,220	111,945
Net income	258,055	250,224	257,888
Other comprehensive income (loss), net	13,327	(24,367)	(8,680)
Comprehensive income	$ 271,382	$ 225,857	$ 249,208

Parent Company Information - _3

Parent Company Information - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net Income (Loss)	$ 258,055	$ 250,224	$ 257,888
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	70,557	61,446	53,447
Amortization of operating lease right-of-use assets	5,853	5,708	6,799
Stock-based compensation expense	29,190	29,864	27,314
Deferred taxes	(5,815)	(6,547)	3,118
Other	(3,113)	555	(466)
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(7,116)	(15,136)	15,598
Decrease/(increase) in prepaid expenses and other assets	(11,898)	(4,249)	2,214
(Decrease) increase in accrued employee compensation	1,466	(3,417)	(2,607)
Increase (decrease) in income and other tax liabilities	(14,691)	(4,768)	(5,638)
(Decrease)/increase in accounts payable, accrued expenses and other liabilities	(7,229)	11,384	215
(Decrease) in operating lease liabilities	(6,735)	(6,373)	(7,001)
Net cash provided by operating activities	333,767	289,231	282,091
Cash flows from investing activities
Acquisitions, net of cash and cash equivalents acquired	(78,476)	0	(17,078)
Acquisition of equity method investment	0	(34,400)	0
Proceeds from maturities and sales	4,452	0	0
Purchases	(28,818)	0	0
Purchases of furniture, equipment and leasehold improvements	(9,326)	(13,142)	(17,493)
Net cash (used in) investing activities	(155,290)	(86,272)	(67,694)
Cash flows from financing activities
Cash dividend on common stock	(109,658)	(105,942)	(99,792)
Exercise of stock options	940	672	7,096
Withholding tax payments on restricted stock vesting and stock option exercises	(25,839)	(23,404)	(33,890)
Repurchases of common stock	0	(87,540)	(63,189)
Proceeds from short-term borrowings	123,995	100,000	70,348
Repayments of short-term borrowings	(123,995)	(100,000)	(70,348)
Net cash (used in) financing activities	(147,057)	(242,378)	(189,775)
Effect of exchange rate changes on investments	7,588	(13,484)	(7,105)
Cash and cash equivalents including restricted cash
Net increase (decrease) for the period	39,008	(52,903)	17,517
Beginning of period	572,664	625,567	608,050
End of period	611,672	572,664	625,567
Supplemental cash flow information:
Cash paid for income taxes	94,814	88,677	70,003
Cash paid for interest	1,870	652	830
Non-cash investing and financing activity:
Exercise of stock options - cashless	0	3,845	2,750
Right-of-use assets obtained in exchange for operating lease liabilities	1,183	1,880	1,972
Treasury stock used for acquisition of business	(43,841)	0	0
MarketAxess Holdings Inc. (Parent) [Member]
Cash flows from operating activities
Net Income (Loss)	258,055	250,224	257,888
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,153	2,136	2,123
Amortization of operating lease right-of-use assets	3,361	3,347	4,484
Stock-based compensation expense	9,725	12,554	12,706
Deferred taxes	101	(5,076)	1,712
Equity in undistributed income of subsidiaries	(2,221)	(15,220)	(111,945)
Other	(4,675)	441	0
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(1,154)	(769)	178
(Increase) decrease in receivable from subsidiaries	(189)	984	(1,516)
Decrease/(increase) in prepaid expenses and other assets	1,296	1,175	219
(Increase) decrease in income and other tax receivables	3,800	(9,711)	7,265
(Decrease) increase in accrued employee compensation	(1,104)	(1,372)	824
Increase (decrease) in income and other tax liabilities	2,287	62	(143)
(Decrease)/increase in accounts payable, accrued expenses and other liabilities	(861)	443	(607)
(Decrease) in operating lease liabilities	(3,624)	(3,689)	(4,673)
Net cash provided by operating activities	272,424	241,110	215,449
Cash flows from investing activities
Acquisitions, net of cash and cash equivalents acquired	(81,161)	0	(17,079)
Acquisition of equity method investment	0	(34,400)	0
Investments in subsidiaries	(10,058)	(8,326)	0
Proceeds from maturities and sales	4,454	0	0
Purchases	(28,818)	0	0
Purchases of furniture, equipment and leasehold improvements	(239)	(96)	(198)
Net cash (used in) investing activities	(115,822)	(42,822)	(17,277)
Cash flows from financing activities
Cash dividend on common stock	(109,658)	(105,942)	(99,791)
Exercise of stock options	940	672	7,096
Withholding tax payments on restricted stock vesting and stock option exercises	(25,839)	(23,404)	(33,890)
Repurchases of common stock	0	(87,540)	(63,189)
Proceeds from short-term borrowings	100,000	100,000	0
Repayments of short-term borrowings	(100,000)	(100,000)	0
Net cash (used in) financing activities	(134,557)	(216,214)	(189,774)
Effect of exchange rate changes on investments	(3)	15	(2,324)
Cash and cash equivalents including restricted cash
Net increase (decrease) for the period	22,042	(17,911)	6,073
Beginning of period	43,909	61,820	55,747
End of period	65,951	43,909	61,820
Supplemental cash flow information:
Cash paid for income taxes	55,784	65,764	41,103
Cash paid for interest	35	271	0
Non-cash investing and financing activity:
Exercise of stock options - cashless	0	3,845	2,750
Right-of-use assets obtained in exchange for operating lease liabilities	1,072	0	0
Treasury stock used for acquisition of business	43,841	0	0
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
(Increase) in trading investments	(1,103)	1,813	(2,306)
Mutual Funds Held In Rabbi Trust [Member] | MarketAxess Holdings Inc. (Parent) [Member]
Changes in operating assets and liabilities:
(Increase) in trading investments	5,474	7,931	47,371
Trading Investments [Member]
Changes in operating assets and liabilities:
(Increase) in trading investments	$ (25,248)	$ (49,527)	$ (5,574)