Tradeweb Markets (TW) 10-K 21 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 14, 2020	Jun. 28, 2019
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Entity Registrant Name	Tradeweb Markets Inc.
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Public Float			$ 4.5
Entity Central Index Key	0001758730
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A common stock
Entity Common Stock, Shares Outstanding		70,212,713
Class B common stock
Entity Common Stock, Shares Outstanding		96,933,192
Class C common stock
Entity Common Stock, Shares Outstanding		7,389,983
Class D common stock
Entity Common Stock, Shares Outstanding		49,873,346

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Assets
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Successor
Cash and cash equivalents	$ 410,104	$ 460,711	$ 460,711	$ 410,104
Restricted cash	1,200	1,000	1,000	1,200
Receivable from brokers and dealers and clearing organizations	174,591	30,641	30,641	174,591
Deposits with clearing organizations	11,427	9,724	9,724	11,427
Accounts receivable, net of allowance	87,192	92,814	92,814	87,192
Furniture, equipment, purchased software and leasehold improvements, net of accumulated depreciation and amortization	38,128	40,405	40,405	38,128
Right-of-use assets		24,504	24,504
Software development costs, net of accumulated amortization	170,582	173,086	173,086	170,582
Goodwill	2,694,797	2,694,797	2,694,797	2,694,797
Intangible assets, net of accumulated amortization	1,380,848	1,281,441	1,281,441	1,380,848
Receivable from affiliates	3,243	2,525	2,525	3,243
Deferred tax asset		256,450	256,450
Other assets	25,027	27,236	27,236	25,027
Total assets	4,997,139	5,095,334	5,095,334	4,997,139
Liabilities
Payable to brokers and dealers and clearing organizations	171,214	30,452	30,452	171,214
Accrued compensation	120,158	119,415	119,415	120,158
Deferred revenue	27,883	23,990	23,990	27,883
Accounts payable, accrued expenses and other liabilities	42,548	32,834	32,834	42,548
Employee equity compensation payable	24,187	1,048	1,048	24,187
Lease liability		30,955	30,955
Payable to affiliates	5,009	1,506	1,506	5,009
Deferred tax liability	19,627	21,572	21,572	19,627
Tax receivable agreement liability		240,817	240,817
Total liabilities	410,626	502,589	502,589	410,626
Commitments and contingencies (Note 17)
Mezzanine Capital
Class C Shares and Class P(C) Shares	14,179			14,179
Stockholders' Equity/Members' Capital
Members’ capital	4,573,200			4,573,200
Preferred stock, $.00001 par value; 250,000,000 shares authorized; none issued or outstanding
Additional paid-in capital		3,329,386	3,329,386
Accumulated other comprehensive income (loss)	(866)	1,366	1,366	(866)
Retained earnings		47,833	47,833
Total stockholders' equity attributable to Tradeweb Markets Inc./members' capital	4,572,334	3,378,588	3,378,588	4,572,334
Non-controlling interests		1,214,157	1,214,157
Total equity	4,572,334	4,592,745	4,592,745	4,572,334
Total liabilities and stockholders' equity/members' capital	$ 4,997,139	5,095,334	5,095,334	$ 4,997,139
Class A common stock
Stockholders' Equity/Members' Capital
Common stock		1	1
Total equity		1	1
Class B common stock
Stockholders' Equity/Members' Capital
Common stock		1	1
Total equity		1	1
Class D common stock
Stockholders' Equity/Members' Capital
Common stock		1	1
Total equity		$ 1	$ 1
Tradeweb Markets LLC
Assets
Financial Designation, Predecessor and Successor [Fixed List]	Successor

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	250,000,000	250,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A common stock
Common Stock, par value per share	$ 0.00001
Common Stock, shares authorized	1,000,000,000
Common stock, shares outstanding	66,408,328
Class B common stock
Common Stock, par value per share	$ 0.00001
Common Stock, shares authorized	450,000,000
Common stock, shares outstanding	96,933,192
Class C common stock
Common Stock, par value per share	$ 0.00001
Common Stock, shares authorized	350,000,000
Common stock, shares outstanding	8,328,983
Class D common stock
Common Stock, par value per share	$ 0.00001
Common Stock, shares authorized	300,000,000
Common stock, shares outstanding	50,853,172

Consolidated Statements of Inco

Consolidated Statements of Income $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Revenues
Financial Designation, Predecessor and Successor [Fixed List]	Successor
Gross revenue	$ 775,566
Net revenue	775,566
Expenses
Employee compensation and benefits	329,457
Depreciation and amortization	139,330
Technology and communications	39,285
General and administrative	34,960
Professional fees	28,029
Occupancy	14,686
Total expenses	585,747
Operating income	189,819
Tax receivable agreement liability adjustment	33,134
Net interest income	2,373
Income before taxes	225,326
Provision for income taxes	(52,302)
Net income	173,024
Less: Pre-IPO net income attributable to Tradeweb Markets LLC	83,769
Net income attributable to Tradeweb Markets Inc. and non-controlling interests	130,672
Less: Net income attributable to non-controlling interests	46,903
Net income attributable to Tradeweb Markets Inc.	$ 83,769
EPS calculations for pre-IPO and post-IPO periods
Basic | $ / shares	$ 0.57
Diluted | $ / shares	$ 0.54
Weighted average shares outstanding
Basic | shares	148,013,274
Diluted | shares	156,540,246
Transaction fees
Revenues
Gross revenue	$ 423,583
Subscription fees
Revenues
Gross revenue	138,731
Commissions
Revenues
Gross revenue	149,365
Refinitiv market data fees
Revenues
Gross revenue	55,635
Other
Revenues
Gross revenue	8,252
Tradeweb Markets LLC
Expenses
Less: Pre-IPO net income attributable to Tradeweb Markets LLC	42,352
Net income attributable to Tradeweb Markets Inc.	$ 42,352
EPS calculations for pre-IPO and post-IPO periods
Basic | $ / shares	$ 0.19
Diluted | $ / shares	$ 0.19
Weighted average shares outstanding
Basic | shares	222,222,197
Diluted | shares	223,320,457

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2017
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Predecessor	Successor	Predecessor
Net income attributable to Tradeweb Markets			$ 83,769
Foreign currency translation adjustments attributable to non-controlling interests			1,441
Total comprehensive income		$ 127,096	85,210	$ 86,533
Net income attributable to non-controlling interests			46,903
Foreign currency translation adjustments attributable to noncontrolling interests			298
Comprehensive income attributable to non-controlling interests			47,201
Tradeweb Markets LLC
Financial Designation, Predecessor and Successor [Fixed List]	Successor
Net income attributable to Tradeweb Markets	$ 29,307	130,160	42,352	83,648
Foreign currency translation adjustments attributable to non-controlling interests	(866)	(3,064)	988	2,885
Total comprehensive income	$ 28,441	$ 127,096	$ 43,340	$ 86,533

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Equity Incentive PlanClass A common stock	Members' Capital	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Non-Controlling Interests	Class A common stock	Class B common stock	Class C common stock	Class D common stock	Total
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Predecessor
Members' capital beginning of period at Dec. 31, 2016		$ 1,040,911		$ (16,152)							$ 1,024,759
Comprehensive income:
Adjustment to Class C Shares and Class P© shares in mezzanine capital		(2,109)									(2,109)
Capital distributions		(152,000)									(152,000)
Net income		83,648									83,648
Foreign currency translation adjustments				2,885							2,885
Total comprehensive income		83,648		2,885							86,533
Capital contributions		29,285									29,285
Members' capital end of period at Dec. 31, 2017		999,735		(13,267)							$ 986,468
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Predecessor
Comprehensive income:
Adjustment to Class C Shares and Class P© shares in mezzanine capital		456									$ 456
Capital distributions		(139,350)									(139,350)
Net income		130,160									130,160
Foreign currency translation adjustments				(3,064)							(3,064)
Vesting of contingent consideration		150,495									150,495
Total comprehensive income		130,160		(3,064)							127,096
Members' capital end of period at Sep. 30, 2018		1,141,496		(16,331)							$ 1,125,165
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Successor
Members' capital beginning of period at Dec. 31, 2017		999,735		(13,267)							$ 986,468
Members' capital end of period at Dec. 31, 2018		4,573,200		(866)							4,572,334
Equity at end of period at Dec. 31, 2018				(866)							$ 4,572,334
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Successor
Members' capital beginning of period at Sep. 30, 2018		1,141,496		(16,331)							$ 1,125,165
Comprehensive income:
Net income											29,307
Members' capital end of period at Dec. 31, 2018		4,573,200		(866)							4,572,334
Equity at end of period at Dec. 31, 2018				(866)							4,572,334
Members' capital beginning of period at Oct. 01, 2018		4,562,154									4,562,154
Comprehensive income:
Adjustment to Class C Shares and Class P© shares in mezzanine capital		(1,333)									(1,333)
Capital distributions		(36,000)									(36,000)
Net income		29,307									29,307
Foreign currency translation adjustments				(866)							(866)
Total comprehensive income		29,307		(866)							28,441
Conversion of certain cash-settled PRSUs to equity-settled PRSUs		19,072									19,072
Members' capital end of period at Dec. 31, 2018		4,573,200		(866)							4,572,334
Equity at end of period at Dec. 31, 2018				(866)							$ 4,572,334
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Successor
Comprehensive income:
Adjustment to Class C Shares and Class P© shares in mezzanine capital		(2,369)									$ (2,369)
Capital distributions		(20,000)									(20,000)
Stock-based compensation		4,674									4,674
Net income		42,352									42,352
Foreign currency translation adjustments				988							988
Members' capital end of period at Mar. 31, 2019		4,597,857
Equity at end of period at Mar. 31, 2019				122							$ 4,597,979
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Successor
Members' capital beginning of period at Dec. 31, 2018		4,573,200		(866)							$ 4,572,334
Equity at beginning of period at Dec. 31, 2018				(866)							4,572,334
Comprehensive income:
Stock-based compensation expense under the PRSU Plan											19,100
Net income											173,024
Total comprehensive income											85,210
Equity at end of period at Dec. 31, 2019			$ 3,329,386	1,366	$ 47,833	$ 1,214,157	$ 1	$ 1		$ 1	$ 4,592,745
Equity at end of period (in shares) at Dec. 31, 2019							66,408,328	96,933,192	8,328,983	50,853,172
Increase (Decrease) in Stockholders' Equity
Financial Designation, Predecessor and Successor [Fixed List]											Successor
Members' capital beginning of period at Mar. 31, 2019		4,597,857
Equity at beginning of period at Mar. 31, 2019				122							$ 4,597,979
Comprehensive income:
Capital distributions		(100,000)									(100,000)
Effect of the reorganization transactions		$ (4,497,857)	4,521,132								23,275
Issuance of common stock			(18,492)					$ 1		$ 1	(18,490)
Issuance of common stock (in shares)	301,478						46,000,000	96,933,192	10,006,269	69,282,736
Activities related to the follow-on offering and other exchanges of LLC Interests, net of offering costs and cancellations							$ 1				1
Activities related to the follow-on offering and other exchanges of LLC Interests, net of offering costs and cancellations (in shares)							20,106,850		(1,677,286)	(18,429,564)
Tax receivable agreement liability and deferred taxes arising from the reorganization transactions, IPO and follow-on offering and other LLC Interest ownership changes			(4,382)								(4,382)
Allocation of equity to non-controlling interests			(1,607,529)			1,607,529
Adjustments to non-controlling interests			402,424	(197)		(402,227)
Distributions to non-controlling interests						(38,346)					(38,346)
Dividends ($0.24 per share)					(35,936)						(35,936)
Stock-based compensation expense under the PRSU Plan			20,718								20,718
Stock-based compensation expense under the Option Plan			24,432								24,432
Payroll taxes paid for stock-based compensation exercises			(8,917)								(8,917)
Net income					83,769	46,903					130,672
Foreign currency translation adjustments				1,441		298					1,739
Equity at end of period at Dec. 31, 2019			$ 3,329,386	$ 1,366	$ 47,833	$ 1,214,157	$ 1	$ 1		$ 1	$ 4,592,745
Equity at end of period (in shares) at Dec. 31, 2019							66,408,328	96,933,192	8,328,983	50,853,172

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2017
Cash flows from operating activities
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Predecessor	Successor	Predecessor
Net income	$ 29,307	$ 130,160	$ 173,024	$ 83,648
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33,020	48,808	139,330	68,615
Contingent consideration		26,830		58,520
Vesting of P-1 (C) Shares		(5,728)
Stock-based compensation expense			49,824
Deferred taxes	968	2,602	15,024	(950)
Tax receivable agreement liability adjustment			(33,134)
(Increase) decrease in operating assets:
Receivable from/Payable to brokers and dealers and clearing organizations, net	1,265	(4,640)	3,188	(2)
Deposits with clearing organizations	(2,248)	726	1,789	606
Accounts receivable	8,085	(28,434)	(4,283)	11,196
Receivable from/Payable to affiliates, net	(1,102)	(1,850)	(2,461)	(135)
Other assets	(4,695)	(6,371)	(5,648)	4,719
Increase (decrease) in operating liabilities:
Accrued compensation	38,368	(7,568)	(1,783)	12,364
Deferred revenue	(396)	(1,396)	(3,905)	(12,555)
Accounts payable, accrued expenses and other liabilities	639	8,793	(3,550)	(3,826)
Employee equity compensation payable	9,345	2,896	(16,412)	2,380
Net cash provided by operating activities	112,556	164,828	311,003	224,580
Cash flows from investing activities
Purchase of furniture, equipment, software and leasehold improvements	(9,090)	(6,327)	(15,781)	(13,461)
Capitalized software development costs	(7,156)	(19,523)	(28,681)	(27,157)
Business acquisitions				66
Purchase of investments				(5,000)
Net cash used in investing activities	(16,246)	(25,850)	(44,462)	(45,552)
Cash flows from financing activities
Mezzanine capital contributions				82
Mezzanine capital distributions				(1,543)
Pre-IPO capital distributions	(36,000)	(139,350)	(120,000)	(152,000)
Proceeds from issuance of Class A common stock in the IPO, net of underwriting discounts			1,161,270
Purchase of LLC Interests and Class A common stock in connection with the IPO			(1,161,270)
Proceeds from issuance of Class A common stock in the follow-on offering			809,954
Purchase of LLC Interests in connection with the follow-on offering			(809,954)
Offering costs from IPO and follow-on offering			(14,943)
Dividends			(35,936)
Capital distributions to non-controlling interests			(38,346)
Payroll taxes paid for stock-based compensation exercises			(8,917)
Net cash used in financing activities	(36,000)	(139,350)	(218,142)	(153,461)
Effect of exchange rate changes on cash and cash equivalents	(389)	(2,043)	2,008	3,157
Net increase (decrease) in cash and cash equivalents	59,921	(2,415)	50,407	28,724
Cash and cash equivalents and restricted cash
Beginning of period	351,383	353,798	411,304	325,074
End of period	411,304	351,383	461,711	353,798
Supplemental disclosure of cash flow information
Interest paid				455
Income taxes paid	2,659	5,500	43,842	6,312
Non-cash financing activities - Items arising from the reorganization transactions, IPO, follow-on offering and other LLC Interest ownership changes:
Deferred tax asset	968	2,602	15,024	(950)
Vesting of contingent consideration		150,495
Conversion of convertible term note payable to Thomson Reuters to Class A Shares				$ 29,285
Conversion of certain cash-settled PRSUs to equity-settled PRSUs	$ 19,072
Refinitiv Transaction
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes			269,569
Non-cash financing activities - Items arising from the reorganization transactions, IPO, follow-on offering and other LLC Interest ownership changes:
Establishment of liabilities under tax receivable agreement			273,951
Deferred tax asset			$ 269,569
Vesting of contingent consideration		$ 150,495

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements of Cash Flows
Cash and cash equivalents	$ 460,711	$ 410,104
Restricted cash	1,000	1,200
Cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 461,711	$ 411,304	$ 351,383	$ 353,798	$ 325,074

Organization

Organization	12 Months Ended
	Dec. 31, 2019
Organization
Organization	Tradeweb Markets Inc. and Subsidiaries Notes to Consolidated Financial Statements 1. Organization Tradeweb Markets Inc. (the “Corporation”) was incorporated as a Delaware corporation on November 7, 2018 for the purpose of completing certain reorganization transactions in order to carry on the business of Tradeweb Markets LLC (“TWM LLC”) and conducting an initial public offering (“IPO”) as described below under “—Initial Public Offering” and “—Reorganization Transactions.” The Corporation is a consolidating subsidiary of BCP York Holdings, (“BCP”) a company owned by certain investment funds affiliated with The Blackstone Group Inc. (f/k/a The Blackstone Group L.P.) (“Blackstone”), through BCP’s majority ownership interest in Refinitiv Holdings Limited (the “Parent” and, unless otherwise stated or the context otherwise requires, together with all of its subsidiaries, “Refinitiv”). Refinitiv owns a majority ownership interest in the Company (as defined below). The Corporation is a holding company whose principal asset is LLC Interests (as defined below) of TWM LLC. As the sole manager of TWM LLC, the Corporation operates and controls all of the business and affairs of TWM LLC and, through TWM LLC and its subsidiaries, conducts the Corporation’s business. As a result of this control, and because the Corporation has a substantial financial interest in TWM LLC, the Corporation consolidates the financial results of TWM LLC and reports a non-controlling interest in the Corporation’s consolidated financial statements. As of December 31, 2019, Tradeweb Markets Inc. owns 73.4% of TWM LLC and the non-controlling interest holders own the remaining 26.6% of TWM LLC. Unless the context otherwise requires, references to the “Company” refer to Tradeweb Markets Inc. and its consolidated subsidiaries, including TWM LLC, following the completion of the Reorganization Transactions (as defined below), and TWM LLC and its consolidated subsidiaries prior to the completion of the Reorganization Transactions. The Company is a leader in building and operating electronic marketplaces for a global network of clients across the institutional, wholesale and retail client sectors. The Company’s principal subsidiaries include: · Tradeweb LLC (“TWL”), a registered broker-dealer under the Securities Exchange Act of 1934, a member of the Financial Industry Regulatory Authority (“FINRA”), a registered independent introducing broker with the Commodities Future Trading Commission (“CFTC”) and a member of the National Futures Association (“NFA”). · Dealerweb Inc. (“DW”) (formerly known as Hilliard Farber & Co., Inc.). DW is a registered broker-dealer under the Securities Exchange Act of 1934 and a member of FINRA. DW is also registered as an introducing broker with the CFTC and NFA. · Tradeweb Direct LLC (“TWD”) (formerly known as BondDesk Trading LLC), a registered broker-dealer under the Securities Exchange Act of 1934 and a member of FINRA. · Tradeweb Europe Limited (“TEL”), a Multilateral Trading Facility regulated by the Financial Conduct Authority (the “FCA”) in the UK, which maintains branches in Asia which are regulated by certain Asian securities regulators. · TW SEF LLC (“TW SEF”), a Swap Execution Facility (“SEF”) regulated by the CFTC. · DW SEF LLC (“DW SEF”), a SEF regulated by the CFTC. · Tradeweb Japan K.K. (“TWJ”), a security house regulated by the Japanese Financial Services Agency (“JFSA”) and the Japan Securities Dealers Association (“JSDA”). · Tradeweb EU B.V. (“TWEU”), a Trading Venue and Approved Publication Arrangement regulated by the Netherlands Authority for the Financial Markets (“AFM”). Acquisition of Parent Company and Presentation of Financial Statements A majority interest of Refinitiv (formerly the Thomson Reuters Financial & Risk Business) was acquired by BCP on October 1, 2018 (the “Refinitiv Transaction”) from Thomson Reuters Corporation (“TR”). The accompanying consolidated financial statements are presented for two periods: predecessor and successor, which relate to the periods preceding and succeeding the Refinitiv Transaction, respectively. The Refinitiv Transaction results in a new basis of accounting beginning on October 1, 2018 and the financial reporting periods are presented as follows: · The successor period of the Company, reflecting the Refinitiv Transaction, as of and for the year ended December 31, 2019 and as of December 31, 2018 and for the period from October 1, 2018 to December 31, 2018 (the “2018 Successor Period”) . · The predecessor period of the Company for the period from January 1, 2018 to September 30, 2018 (the “2018 Predecessor Period”) and the year ended December 31, 2017 . See Note 3 – Pushdown Accounting. Initial Public Offering On April 8, 2019, the Corporation completed its IPO of 46,000,000 shares of Class A common stock, par value $0.00001 per share, of the Corporation (the “Class A common stock”) at a public offering price of $27.00, which included 6,000,000 shares of Class A common stock issued pursuant to the underwriters’ option to purchase additional shares of Class A common stock. The Corporation received $1.2 billion in net proceeds, after deducting underwriting discounts and commissions but before deducting offering expenses, which were used to purchase membership interests of TWM LLC from certain existing equity holders of TWM LLC (and the corresponding shares of common stock were cancelled as described below), at a purchase price per interest equal to the public offering price of $27.00, less the underwriting discounts and commissions payable thereon. See Note 11 – Stockholders’ Equity. Reorganization Transactions Prior to the closing of the IPO, a series of reorganization transactions (the “Reorganization Transactions”) was completed among the Corporation, TWM LLC and the owners of TWM LLC prior to the Reorganization Transactions (collectively, the “Original LLC Owners”), including the following parties:  certain investment and commercial banks (collectively, the “Bank Stockholders”);  members of management;  the Refinitiv Direct Owner, (i) prior to June 28, 2019, a direct subsidiary of Refinitiv that owned interests in an entity that held membership interests of TWM LLC prior to the Reorganization Transactions and contributed such entity to the Corporation (the “Refinitiv Contribution”) in exchange for shares of Class B common stock, par value $0.00001 per share, of the Corporation (the “Class B common stock”) in connection with the completion of the Reorganization Transactions and (ii) on and after June 28, 2019, an indirect subsidiary of Refinitiv that owns shares of the Corporation’s Class B common stock which shares were contributed by the direct subsidiary of Refinitiv referred to in the foregoing clause (i); and  an indirect subsidiary (the “Refinitiv LLC Owner” and, together with the Refinitiv Direct Owner, the “Refinitiv Owners”) of Refinitiv. As used herein, references to “Continuing LLC Owners” refer collectively to (i) those Original LLC Owners, including the Refinitiv LLC Owner, certain Bank Stockholders and members of management, that continued to own LLC Interests (as defined below) after the completion of the IPO and Reorganization Transactions, that received shares of Class C common stock, par value $0.00001 per share, of the Corporation (the “Class C common stock”), shares of the Corporation’s Class D common stock or a combination of both, as the case may be, in connection with the completion of the Reorganization Transactions, and that may redeem or exchange their LLC Interests for shares of Class A common stock or Class B common stock and (ii) solely with respect to the Tax Receivable Agreement (as defined below), also includes those Original LLC Owners, including certain Bank Stockholders, that disposed of all of their LLC Interests for cash in connection with the IPO. The following Reorganization Transactions occurred:  TWM LLC’s limited liability company agreement (the “TWM LLC Agreement”) was amended and restated to, among other things, (i) provide for a new single class of common membership interests in TWM LLC (“LLC Interests”), (ii) exchange all of the then existing membership interests in TWM LLC for LLC Interests and (iii) appoint the Corporation as the sole manager of TWM LLC. See Note 11 – Stockholders’ Equity.  The Corporation’s certificate of incorporation was amended and restated to, among other things, provide for Class A common stock, Class B common stock, Class C common stock and Class D common stock. See Note 11 – Stockholders’ Equity. · The Corporation issued 20,000,000 shares of Class C common stock and 105,289,005 shares of Class D common stock to the Original LLC Owners that received LLC Interests on a one-to-one basis with the number of LLC Interests they owned immediately following the amendment and restatement of the TWM LLC Agreement for nominal consideration (and the Corporation subsequently cancelled 9,993,731 shares of such Class C common stock and 36,006,269 shares of such Class D common stock in connection with the Corporation’s purchase of LLC Interests from certain of the Bank Stockholders using the net proceeds of the IPO). · As a result of the Refinitiv Contribution (described above), the Corporation received 96,933,192 LLC Interests and the Refinitiv Direct Owner received 96,933,192 shares of Class B common stock. See Note 11 – Stockholders’ Equity.  The Corporation’s board of directors adopted a new omnibus equity incentive plan, under which equity awards may be made in respect of shares of Class A common stock. It also assumed sponsorship of an option plan and PRSU plan formerly sponsored by TWM LLC. See Note 13 – Stock-Based Compensation Plans.  The Corporation entered into a tax receivable agreement (the “Tax Receivable Agreement”) with TWM LLC and the Continuing LLC Owners. See Note 10 – Tax Receivable Agreement. LSEG Transaction On August 1, 2019, London Stock Exchange Group plc announced that it has agreed to definitive terms with a consortium including certain investment funds affiliated with Blackstone as well as TR to acquire the Refinitiv business in an all share transaction (the “LSEG Transaction”). The LSEG Transaction is subject to customary regulatory approvals and closing conditions, and is expected to close during the second half of 2020. .

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Significant Accounting Policies
Significant Accounting Policies	2. Significant Accounting Policies The following is a summary of significant accounting policies: Basis of Accounting The consolidated financial statements have been presented in conformity with accounting principles generally accepted in the United States of America. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates and the difference may be material to the consolidated financial statements. Basis of Presentation and Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. As discussed in Note 1—Organization, as a result of the Reorganization Transactions, Tradeweb Markets Inc. consolidates TWM LLC and TWM LLC is considered to be the predecessor to Tradeweb Markets Inc. for financial reporting purposes. As a result, the consolidated financial statements for periods prior to the Reorganization Transactions have been adjusted to combine the previously separate entities for presentation purposes. However, Tradeweb Markets Inc. had no business transactions or activities and no substantial assets or liabilities prior to the Reorganization Transactions. As such, for periods prior to the completion of the Reorganization Transactions, the consolidated financial statements represent the historical financial condition and results of operations of TWM LLC and its subsidiaries. For periods after the completion of the Reorganization Transactions, the consolidated financial statements represent the financial condition and results of operations of the Company and report a non-controlling interest related to the LLC Interests held by the other members of TWM LLC. Cash and Cash Equivalents Cash and cash equivalents consists of cash and highly liquid investments (such as short-term money market instruments) with original maturities of less than three months. Allowance for Doubtful Accounts The Company continually monitors collections and payments from its clients and maintains an allowance for doubtful accounts. The allowance for doubtful accounts is based upon the historical collection experience and specific collection issues that have been identified. Additions, if any, to the allowance for doubtful accounts are charged to bad debt expense, which is included in general and administrative expenses on the consolidated statements of income. Receivable from and Payable to Brokers and Dealers and Clearing Organizations Receivable from and payable to brokers and dealers and clearing organizations consists of proceeds from transactions which failed to settle due to the inability of a transaction party to deliver or receive the transacted security. These securities transactions are generally collateralized by those securities. At times, transactions executed on the Company’s wholesale platform fail to settle due to the inability of a transaction party to deliver or receive the transacted security. Until the failed transaction settles, a receivable from (and a matching payable to) brokers and dealers and clearing organizations is recognized for the proceeds from the unsettled transaction. Deposits with Clearing Organizations Deposits with clearing organizations are comprised of cash deposits. Due to the short-term nature of these deposits, the recorded value has been determined to approximate fair value. Furniture, Equipment, Purchased Software and Leasehold Improvements Furniture, equipment, purchased software and leasehold improvements are carried at cost less accumulated depreciation. Depreciation for furniture, equipment and purchased software, including the allocated fair value of assets as a result of pushdown accounting (see Note 3 – Pushdown Accounting), is computed on a straight-line basis over the estimated useful lives of the related assets, ranging from three to seven years. Leasehold improvements are amortized over the lesser of the estimated useful lives of the leasehold improvements or the remaining term of the lease for office space. Furniture, equipment, purchased software and leasehold improvements are tested for impairment whenever events or changes in circumstances suggest that an asset’s carrying value may not be fully recoverable in accordance with Accounting Standards Codification (“ASC”) 360, Property, Plant and Equipment . Software Development Costs The Company capitalizes costs associated with the development of internal use software at the point at which the conceptual formulation, design and testing of possible software project alternatives have been completed, in accordance with ASC 350. The Company capitalizes employee compensation and related benefits and third party consulting costs incurred during the application development stage which directly contribute to such development. Such costs are amortized on a straight-line basis over three years. Costs capitalized as part of the pushdown accounting allocation (see Note 3 – Pushdown Accounting) are amortized over nine 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 fully recoverable, or that their useful lives are shorter than originally expected. Non-capitalized software costs and routine maintenance costs are expensed as incurred. Goodwill Goodwill is the excess of the fair value of the Company above the fair value accounting basis of the net assets and liabilities of the Company under pushdown accounting. Goodwill is also the cost of acquired companies in excess of the fair value of identifiable net assets at the acquisition date. Goodwill is not amortized, but in accordance with ASC 350, goodwill is tested for impairment annually and between annual tests whenever events or changes in circumstances indicate that the carrying amount may not be fully recoverable. Goodwill is tested at the reporting unit level, which is defined as an operating segment or one level below the operating segment. An impairment loss is recognized if the estimated fair value of a reporting unit is less than its net book value. Such loss is calculated as the difference between the estimated fair value of goodwill and its carrying value. In 2019, the Company changed the annual date on which goodwill is tested for impairment from July 1 st to October 1 st to align with the annual impairment testing date of the Company’s Parent. This change did not accelerate, delay, avoid or cause an impairment charge, nor did this change result in adjustments to any previously issued financial statements. Goodwill was last assessed on October 1, 2019. Intangible Assets Intangible assets with a finite life are amortized over the estimated lives, ranging from seven to sixteen years, in accordance with ASC 350. Intangible assets subject to amortization are tested for impairment whenever events or changes in circumstances suggest that an asset's or asset group's carrying value may not be fully recoverable in accordance with ASC 360. Intangible assets with an indefinite useful life are tested for impairment at least annually. An impairment loss is recognized if the sum of the estimated discounted cash flows relating to the asset or asset group is less than the corresponding book value. IPO and Follow-On Offering Costs The Company began incurring costs in connection with the filing of a Registration Statement on Form S-1 for an IPO and a Registration Statement on Form S-1 for a follow-on offering in 2018 and in the third quarter of 2019, respectively. IPO and follow-on offering costs consist of legal, accounting, and other costs directly related to the Company’s efforts to raise capital. In accordance with ASC 505-10-25, Equity , these costs are recognized in additional paid-in capital within the consolidated statements of financial condition when the offering is effective. As of December 31, 2019, $15.9 million of deferred costs related to the IPO and $2.6 million of deferred costs related to the follow-on offering were recognized in additional paid-in capital in the consolidated statements of financial condition. See Note 11 – Stockholders’ Equity. Translation of Foreign Currency Revenues and expenses denominated in foreign currencies are translated at the rate of exchange prevailing at the transaction date. Assets and liabilities denominated in foreign currencies are translated at the rate prevailing at the consolidated statements of financial condition date. Foreign currency re-measurement gains or losses on transactions in nonfunctional currencies are recognized in the consolidated statements of income. Gains or losses on translation in the financial statements of a non-U.S. operation, when the functional currency is other than the U.S. dollar, are included as a component of comprehensive income. Income Tax The Corporation is subject to U.S. federal, state and local income taxes with respect to its taxable income, including its allocable share of any taxable income of TWM LLC, and is taxed at prevailing corporate tax rates. TWM LLC is a multiple member limited liability company taxed as a partnership and accordingly any taxable income generated by TWM LLC is passed through to and included in the taxable income of its members, including the Corporation, on a pro rata basis. Income taxes also include unincorporated business taxes on income earned or losses incurred for conducting business in certain state and local jurisdictions, income taxes on income earned or losses incurred in foreign jurisdictions on certain operations and federal and state income taxes on income earned or losses incurred, both current and deferred, on subsidiaries that are taxed as corporations for U.S. tax purposes. The Company records deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities. The Company measures deferred taxes using the enacted tax rates and laws that will be in effect when such temporary differences are expected to reverse. Based on the weight of the positive and negative evidence considered, management believes that it is more likely than not that the Company will be able to realize its deferred tax assets in the future, therefore, no valuation allowance is necessary. The Company records uncertain tax positions in accordance with ASC 740, Income Taxes on the basis of a two-step process whereby (i) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to income taxes within the provision for income taxes in the consolidated statements of income. Accrued interest and penalties are included within accounts payable, accrued expenses and other liabilities in the consolidated statements of financial condition. The Company has elected to treat taxes due on future U.S. inclusions in taxable income under the global intangible low-taxed income (“GILTI”) provision of the Tax Cuts and Jobs Act as a current period expense when incurred. Deferred Tax Asset Correction During the fourth quarter of 2019, the Company identified and corrected immaterial errors in the calculation of the deferred tax asset associated with the Reorganization Transactions that reduced additional paid-in-capital by $10.2 million and, reduced the deferred tax asset by $10.2 million. This correction relates to immaterial errors associated with inputs (including estimates) used in the calculation of the deferred tax balances related to the Refinitiv Contribution. This correction, if it had been recorded in the interim periods of 2019, would have reduced additional paid-in capital by $10.2 million and reduced the deferred tax asset by $10.2 million at June 30, 2019 and September 30, 2019 and would not have had a material impact on our net assets and would not have had a material impact on our consolidated results of operations or cash flows. Revenue Recognition The Company earns transaction fees from transactions executed on the Company’s trading platforms through various fee plans. Transaction fees are generated both on a variable and fixed price basis and vary by geographic region, product type and trade size. For variable transaction fees, the Company charges clients fees based on the mix of products traded and the volume of transactions executed. Transaction fee revenue is recorded at a point in time when the trade occurs and is generally billed monthly. The Company earns subscription fees from granting access to institutional investors to the Company's electronic marketplaces. Subscription fees are recognized into income in the period that access is provided. Also included in subscription fees are viewer fees from institutional investors accessing fixed income market data. The frequency of subscription fee billings varies from monthly to annually, depending on contract terms. Fees received by the Company which are not yet earned are included in deferred revenue on the consolidated statements of financial condition until the revenue recognition criteria has been met. The Company earns commission revenue from its electronic and voice brokerage services on a riskless principal basis. Riskless principal revenues are derived on matched principal transactions where revenues are earned on the spread between the buy and sell price of the transacted product. Securities transactions and related commission revenue for brokerage transactions are recognized and recorded on a trade-date basis. Commission revenue is collected by the Company when the trade settles or is billed monthly. The Company earns fees from Refinitiv, formerly TR in the predecessor periods, relating to the sale of market data to Refinitiv, which redistributes that data. Included in these fees, which are billed quarterly, are real-time market data fees which are recognized in the period that the data is provided, generally on a monthly basis and historical data sets which are recognized when the historical data set is provided to Refinitiv. On January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers , using the modified retrospective approach. The adoption of ASU 2014-09 did not have a material impact on the measurement or recognition of revenue in any prior reporting periods. However, subsequent to the adoption, the Company was required to make significant judgements for the Refinitiv market data fees. Significant judgements used in accounting for this contract include: · The provision of real-time market data feeds and annual historical data sets are distinct performance obligations. · The performance obligations under this contract are recognized over time from the initial delivery of the data feeds or each historical data set until the end of the contract term. · Determining the transaction price for the performance obligations by using a market assessment analysis. Inputs in this analysis include a consultant study which determined the overall value of the Company's market data and pricing information for historical data sets provided by other companies. Some revenues earned by the Company have fixed fee components, such as monthly minimums or fixed monthly fees, and variable components, such as transaction-based fees. The breakdown of revenues between fixed and variable revenues, in thousands, for the year ended December 31, 2019, the 2018 Successor Period and the 2018 Predecessor Period is as follows: Successor Successor Predecessor Year Ended October 1, 2018 to January 1, 2018 to December 31, 2019 December 31, 2018 September 30, 2018 (in thousands) Variable Fixed Variable Fixed Variable Fixed Revenues Transaction fees $ 325,178 $ 98,405 $ 73,800 $ 23,330 $ 208,049 $ 65,702 Subscription Fees including Refinitiv market data fees 1,736 192,630 425 46,094 1,305 142,676 Commissions 109,995 39,370 22,608 10,232 49,367 30,463 Other 834 7,418 — 2,148 40 8,169 Gross revenue $ 437,743 $ 337,823 $ 96,833 $ 81,804 $ 258,761 $ 247,010 Stock-Based Compensation The Company accounts for stock-based compensation in accordance with ASC 718, Compensation – Stock Compensation . ASC 718 focuses primarily on accounting for a transaction in which an entity obtains employee services in exchange for stock-based payments. Under ASC 718, the stock-based payments received by the employees of the Company are accounted for either as equity awards or as liability awards. As an equity award, the Company measures and recognizes the cost of employee services received in exchange for awards of equity instruments based on their estimated fair values measured as of the grant date. These costs are recognized as an expense over the requisite service period, with an offsetting increase to additional paid-in capital. As a liability award, the cost of employee services received in exchange for an award of equity instruments is generally measured based on the grant-date fair value of the award. The fair value of that award is remeasured subsequently at each reporting date through the settlement in accordance with ASC 505. Changes in the equity instrument's fair value during the requisite service period are recognized as compensation cost over that period. For periods following the Reorganization Transactions and the IPO, the fair value of new equity instrument grants is determined based on the price of the Company’s Class A common stock on the grant date. Under ASC 718, the grant-date fair value of stock-based awards that do not require future service (i.e., vested awards) are expensed immediately. The grant-date fair value of stock-based awards that require future service, and are graded-vesting awards, are amortized over the relevant service period on a straight-line basis, with each tranche separately measured. The grant-date fair value of stock-based awards that require both future service and the achievement of Company performance-based conditions, are amortized over the relevant service period for the performance-based condition. If in a reporting period it is determined that the achievement of a performance target for a performance-based tranche is not probable, then no expense is recognized for that tranche and any expenses already recognized relating to that tranche in prior reporting periods are reversed in the current reporting period. Prior to the IPO, the Company awarded options to management and other employees (collectively, the “Special Option Award”) under the Amended and Restated Tradeweb Markets Inc. Option Plan (the “Option Plan”). In accounting for the options issued under the Option Plan, or which may be issued under the Tradeweb Markets Inc. 2019 Omnibus Equity Incentive Plan (the “Omnibus Equity Plan”) in the future, compensation expense is measured and recognized for all awards based on their estimated fair values measured as of the grant date. Costs related to these options are recognized as an expense in the consolidated statements of income over the requisite service period, with an offsetting increase to additional paid-in capital. In conjunction with the IPO, the non-cash stock-based compensation expense associated with the Special Option Award began being expensed in the second quarter of 2019 and will continue to be expensed over the following three years. Determining the appropriate fair value model and calculating the fair value of the stock-based awards requires the input of highly subjective assumptions, including the expected life of the stock-based awards and the stock price volatility. The Company uses the Black-Scholes pricing model to value some of its stock-based awards. Application of alternative assumptions could produce significantly different estimates of the fair value of stock-based compensation and consequently, the related amounts recognized in the Company’s consolidated statements of income. Earnings Per Share Basic earnings per share is computed by dividing the net income attributable to the Company's shares by the weighted-average number of the Company's shares outstanding during the period. For purposes of computing diluted earnings per share, the weighted-average number of the Company’s shares reflects the dilutive effect that could occur if securities that qualify as participating securities were converted into or exchanged or exercised for TWM LLC’s shares, in the pre-IPO period, and the Class A or Class B common stock, in the post-IPO period, using the treasury stock method, as applicable. Shares of Class C and Class D common stock do not have economic rights in Tradeweb Markets Inc. and, therefore, are not included in the calculation of basic earnings per share and are not participating securities for purposes of the computation of diluted earnings per share. Fair Value Measurement The fair value of a financial instrument is the amount 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 (the exit price). Instruments that the Company owns (long positions) are marked to bid prices, and instruments that the Company has sold, but not yet purchased (short positions) are marked to offer prices. Fair value measurements do not include transaction costs. The fair value hierarchy under ASC 820, Fair Value Measurements prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (level 1 measurements) and the lowest priority to unobservable inputs (level 3 measurements). The three levels of the fair value hierarchy under ASC 820 are described below: Basis of Fair Value Measurement Level 1: Level 2: Level 3: A financial instrument's level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Recent Accounting Pronouncements –Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016‑13, Financial Instruments – Credit Losses . The ASU provides new guidance for estimating credit losses on certain types of financial instruments by introducing an approach based on expected losses. This requires a modified retrospective method of adoption. ASU 2017-04 was adopted on January 1, 2020. The adoption of this ASU di d not have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017‑04, Intangibles – Goodwill and Other . The ASU simplifies the quantitative goodwill impairment test by eliminating the second step of the test. Under this ASU, impairment will be measured by comparing the estimated fair value of the reporting unit with its carrying value. The new guidance does not amend the optional qualitative assessment of goodwill impairment . This new guidance was adopted on January 1, 2020 and had no impact on the Company’s financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in this ASU simplify the accounting for income taxes by removing certain exceptions for investments, intraperiod allocations and interim calculations and include additional guidance in order to reduce complexity in accounting for income taxes. ASU 2019-12 is effective for annual periods beginning after December 15, 2020, with early adoption permitted. This new guidance was early adopted on January 1, 2020 and the adoption of this ASU did not have a material impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , which requires lessees to recognize a right-of-use asset and a lease liability for all leases with an initial term in excess of twelve months. The asset reflects the present value of unpaid lease payments coupled with initial direct costs, prepaid lease payments and lease incentives. The amount of the lease liability is calculated as the present value of unpaid lease payments. ASU 2016-02 was adopted on January 1, 2019 using the modified retrospective method of adoption. Upon adoption, the Company: · Recorded right-of-use assets of $34.8 million, · Recorded a lease liability of $39.6 million, · Eliminated deferred rent of $4.9 million, · Eliminated leasehold interests of $2.9 million, · Elected to take the optional package of practical expedients, which allows for no reassessment of i. whether any expired or existing contracts are or contain leases, ii. the lease classification for any expired or existing leases, and iii. initial direct costs for any existing leases.

Pushdown Accounting

Pushdown Accounting	12 Months Ended
	Dec. 31, 2019
Pushdown Accounting
Pushdown Accounting	3. Pushdown Accounting The Refinitiv Transaction was accounted for by Refinitiv in accordance with the acquisition method of accounting pursuant to ASC 805, and pushdown accounting was applied to Refinitiv to record the fair value of the assets and liabilities of Refinitiv as of October 1, 2018, the date of the Refinitiv Transaction. The Company, as a consolidating subsidiary of Refinitiv, also accounted for the Refinitiv Transaction using pushdown accounting. Under pushdown accounting, the excess of the fair value of the Company above the fair value accounting basis of the net assets and liabilities of the Company is recorded as goodwill. The fair value of assets acquired and liabilities assumed was determined based on assumptions that reasonable market participants would use in the principal (or most advantageous) market for the asset or liability. The adjusted valuations resulted in an increase in depreciation and amortization expense, due to the increased carrying value of the Company’s assets and the related increase in depreciation of tangible assets and amortization of intangible assets, and a decrease in occupancy expense as a result of the recognition of a leasehold interest liability. A fair value of $168.5 million was also assigned to software development costs of the Company. The excess of the fair value of the Company above the fair value accounting basis of the net assets and liabilities of the Company was recorded as goodwill. The allocation applying pushdown accounting as of October 1, 2018 is summarized in the table below (in thousands): Fair Value of the Company's Net Assets $ 4,575,000 Carrying Value of the Company's Net Assets 1,880,203 Goodwill $ 2,694,797 At December 31, 2019 and December 31, 2018, goodwill amounted to $2.7 billion.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2019
Intangible Assets and Goodwill
Intangible Assets and Goodwill	4. Intangible Assets and Goodwill Intangible assets and goodwill relate to the allocation of purchase price associated with the Refinitiv Transaction (see Note 3 – Pushdown Accounting). The following is a summary of intangible assets which have an indefinite useful life at both December 31, 2019 and 2018 (in thousands): Amount Licenses $ 168,800 Tradename 154,300 Total $ 323,100 Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised as follows (in thousands): Successor Successor December 31, 2019 December 31, 2018 Amortization Accumulated Net Carrying Accumulated Net Carrying Period Cost Amortization Amount Cost Amortization Amount Customer relationships 12 Years $ 928,200 $ (96,687) $ 831,513 $ 928,200 $ (19,338) $ 908,862 Content and data 7 Years 154,400 (27,572) 126,828 154,400 (5,514) 148,886 $ 1,082,600 $ (124,259) $ 958,341 $ 1,082,600 $ (24,852) $ 1,057,748 Amortization expense relating to intangible assets was $99.4 million year ended December 31, 2019. Amortization expense relating to intangible assets for the 2018 Successor Period and the 2018 Predecessor Period was $24.9 million and $19.6 million, respectively. The estimated annual future amortization for existing intangible assets through December 31, 2024 is as follows (in thousands): Amount 2020 $ 99,408 2021 99,408 2022 99,408 2023 99,408 2024 99,408

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases
Leases	5. Leases Effective January 1, 2019, the Company adopted ASC 842, Leases . This standard requires the Company to recognize a right-of-use asset and a lease liability for all leases with an initial term in excess of twelve months. The Company includes the term covered by an option to extend a lease when the option is reasonably certain to be exercised. The asset reflects the present value of unpaid lease payments coupled with initial direct costs, prepaid lease payments and lease incentives. The amount of the lease liability is calculated as the present value of unpaid lease payments. The Company adopted ASC 842 using a modified retrospective approach and did not restate comparative periods. The Company elected to take the package of practical expedients allowing the Company to not reassess (i) whether any expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases and (iii) initial direct costs for any existing leases. The Company has elected to account for nonlease components in a contract as part of the single lease component to which they are related. Significant assumptions and judgements in calculating the right-of-use assets and lease liability include the determination of the applicable borrowing rate for each lease. On January 1, 2019, upon the adoption of ASC 842, the Company recorded, for office space and data center leases in the U.S. and U.K., right-of-use assets of $31.8 million, lease liabilities of $39.6 million and eliminated deferred rent of $4.9 million and leasehold interests of $2.9 million. The leases have initial lease terms ranging from three to 11 years. Activity related to the Company's leases for the year ended December 31, 2019 is as follows (in thousands): Year Ended December 31, 2019 Operating lease expense $ 10,265 Cash for amounts included in the measurement of operating liability $ 11,667 Right-of-use assets obtained in exchange for operating liabilities $ — At December 31, 2019, the weighted average borrowing rate and weighted average lease term are as follows: Amount Weighted average borrowing rate 2.9 % Weighted average remaining lease term (years) 5.9 The following table presents the maturity of lease liabilities as of December 31, 2019 (in thousands): Amount 2020 $ 8,516 2021 5,946 2022 4,143 2023 3,956 2024 3,558 Thereafter 7,633 Total future lease payments 33,752 Less imputed interest (2,797) Lease liability $ 30,955 At December 31, 2019, the future minimum lease payments were as follows (in thousands): Amount 2020 $ 8,516 2021 5,946 2022 4,143 2023 3,956 2024 3,558 Thereafter 7,633 Total $ 33,752 At December 31, 2018, the future minimum lease payments were as follows (in thousands): Amount 2019 $ 11,393 2020 7,580 2021 5,317 2022 4,051 2023 3,877 Thereafter 11,156 Total $ 43,374 Rent expense amounted to $2.7 million, $9.0 million and $11.8 million for the 2018 Successor Period, 2018 Predecessor Period and the year ended December 31, 2017, respectively. One U.S. lease is secured by a letter of credit in the amount of $1.2 million, which is guaranteed by Refinitiv.

Restricted Cash

Restricted Cash	12 Months Ended
	Dec. 31, 2019
Restricted Cash
Restricted Cash	6. Restricted Cash Cash has been segregated in a special reserve bank account for the benefit of brokers and dealers under SEC Rule 15c3-3. The Company computes the proprietary accounts of other broker-dealers (“PAB”) reserve, which requires the Company to maintain minimum segregated cash in the amount of total credits per the reserve computation. As of December 31, 2019 and December 31, 2018, cash in the amount of $1.0 million and $1.2 million, respectively, has been segregated in the PAB reserve account exceeding the requirements pursuant to SEC Rule 15c3-3.

Deferred Revenue

Deferred Revenue	12 Months Ended
	Dec. 31, 2019
Deferred Revenue
Deferred Revenue	7. Deferred Revenue The Company records deferred revenue when cash payments are received or due in advance of services to be performed. The recognized revenue and remaining balance is shown below (in thousands): Amount Deferred revenue balance - December 31, 2018 $ 27,883 New billings 106,153 Revenue recognized (110,046) Deferred revenue balance - December 31, 2019 $ 23,990

Software Development Cost

Software Development Cost	12 Months Ended
	Dec. 31, 2019
Software Development Cost
Software Development Cost	8. Software Development Costs The components of Software development costs, net of accumulated amortization are as follows (in thousands): Successor Successor Year Ended Year Ended December 31, December 31, 2019 2018 Software development costs $ 204,336 $ 175,656 Accumulated amortization (31,250) (5,074) Software development costs, net of accumulated amortization $ 173,086 $ 170,582 Capitalized software development costs and non-capitalized software costs and routine maintenance costs are as follows (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 January 1, 2018 Year Ended December 31, to to December 31, 2019 December 31, 2018 September 30, 2018 2017 Software development costs capitalized $ 26,681 $ 7,156 $ 19,523 $ 27,157 Amortization expense related to capitalized software development costs $ 26,176 $ 5,074 $ 19,962 $ 25,420 Non-capitalized software costs and routine maintenance costs are expensed as incurred and are included in employee compensation and benefits and professional fees on the consolidated statements of income.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes
Income Taxes	9. Income Taxes For the year ended December 31, 2019, total income before the provision for income taxes amounted to $225.3 million, consisting of $207.7 million in the United States and $17.6 million in foreign locations. The provision for income taxes consists of the following (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Current: Federal $ 21,373 $ — $ — $ — State and Local 11,537 1,235 5,739 4,331 Foreign 4,368 1,212 3,559 2,748 Total current tax expense 37,278 2,447 9,298 7,079 Deferred: Federal (88) 680 1,085 (433) State and local 18,194 288 1,517 (517) Foreign (3,082) — — — Total deferred tax expense 15,024 968 2,602 (950) Total provision for income taxes $ 52,302 $ 3,415 $ 11,900 $ 6,129 A reconciliation of the statutory tax rate to the effective rate is as follows: Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Statutory U.S. federal income tax rate 21.0 % 21.0 % 21.0 % 35.0 % State and local income taxes, net of federal income tax benefit 3.9 4.7 5.1 2.8 Foreign tax rate differential (1.1) 3.7 2.5 3.1 Tax Cuts and Jobs Act Provisional Tax Charge — — — 2.2 LLC flow-through structure — (19.0) (20.2) (36.3) Non-Controlling Interest (7.2) — — — Tax Receivable Agreement adjustment (3.1) — — — Rate Change 10.2 — — — Other (0.5) — — — Effective income tax rate $ 23.2 % $ 10.4 % $ 8.4 % $ 6.8 % The Company’s consolidated effective tax rate for the year-ended December 31, 2019 was 23.2% as compared to 10.4% in the 2018 Successor Period and 8.4% in the 2018 Predecessor period. The effective tax rate increased from prior periods due to the Reorganization Transactions. Prior to the Reorganization Transactions, income taxes consisted only of business taxes incurred by TWM LLC and certain subsidiaries for business conducted in certain state, local and foreign jurisdictions as well as federal, state and local taxes for certain subsidiaries that are taxed as corporations for U.S. tax purposes. As a result of the Reorganization Transactions, the Corporation is subject to U.S. federal, state and local income taxes with respect to its taxable income, including its allocable share of any taxable income of TWM LLC, and is taxed at prevailing corporate tax rates. The Company’s actual effective tax rate will be impacted by the Corporation’s ownership share of TWM LLC, which is expected to increase over time as the Continuing LLC Owners redeem or exchange their LLC Interests for shares of Class A common stock or Class B common stock, as applicable, or the Corporation purchases LLC Interests from the Continuing LLC Owners. In addition to the Reorganization Transactions, the tax impact of rate changes on total tax expense was 10.2% in 2019 due to the reduction of the Company’s net deferred tax asset. The Company's consolidated effective tax rate will also vary from period to period depending on changes in the geographic mix of its earnings and changes in tax legislation and tax rates. The components of the Company’s net deferred tax asset (liability) are as follows (in thousands): Successor Successor Year Ended Year Ended December 31, December 31, 2019 2018 Deferred tax assets: Investment in partnership $ 226,241 $ — Net operating losses 1,753 6,810 Tax Receivable Agreement - Interest 10,395 — Employee compensation 9,888 — Credits 8,342 — Other 4,088 2,362 Deferred tax assets, gross 260,707 9,172 Valuation Allowance — — Total deferred tax assets, net 260,707 9,172 Deferred tax liabilities Goodwill and Intangibles (25,829) (28,799) Total deferred tax liabilities (25,829) (28,799) Total net deferred tax asset (liability) $ 234,878 $ (19,627) The Company expects to obtain an increase in its share of the tax basis of the assets of TWM LLC when LLC Interests are redeemed or exchanged by the Continuing LLC Owners and in connection with certain other qualifying transactions. This increase in tax basis may have the effect of reducing the amounts that the Corporation would otherwise pay in the future to various tax authorities. Pursuant to the Tax Receivable Agreement, the Corporation is required to make cash payments to the Continuing LLC Owners equal to 50% of the amount of U.S. federal, state and local income or franchise tax savings, if any, that the Corporation actually realizes (or in some circumstances are deemed to realize) as a result of certain future tax benefits to which we may become entitled. The Corporation expects to benefit from the remaining 50% of tax benefits, if any, that the Corporation may actually realize. See Note 10 – Tax Receivable Agreement. As a result of the reorganization transactions, the IPO, the October 2019 follow-on offering and LLC Interest ownership changes during the year ended December 31, 2019, the Company assumed a deferred tax benefit of $216.2 million, primarily due to an increase in amortizable tax basis that will be amortized primarily over 15 years pursuant to Section 197 of the Internal Revenue Code of 1986, as amended, offset by other factors. The tax benefit has been recognized in deferred tax asset on the December 31, 2019 consolidated statement of financial condition. As of December 31, 2019, the Company had New York State and New York City net operating loss carryforwards for income tax purposes of $15.7 million and $13.9 million, respectively. If not utilized, the state and local net operating loss carryforwards will begin to expire in 2035. The components of the Company’s uncertain tax positions are as follows (dollars in thousands): Successor December 31, 2019 Gross unrecognized tax benefits as of January 1 $ 3,348 Increase in current year tax positions 2,162 Increase in prior year tax positions - Acquired tax positions 1,789 Settlements (787) Gross unrecognized tax benefits as of December 31 $ 6,512 The Company recognizes interest and penalties related to income taxes within the provision for income taxes in the consolidated statements of income. Accrued interest and penalties are included within accounts payable, accrued expenses and other liabilities in the consolidated statements of financial condition. The total amount of interest and penalties accrued as of December 31, 2019 are $2.3 million and $0.5 million respectively. In 2019, TWM LLC settled its audits with the City of New York related to New York City Unincorporated Business Tax for years 2009 – 2011. Through the settlement, the Company reduced its uncertain tax positions by $1.3 million. TWM LLC is still under audit by the City of New York for the tax years 2012 – 2014. As a result of the Refinitiv Contribution, the Company assumed the tax liabilities of the contributed entity. The contributed entity is under audit by the State of New Jersey for the tax years 2012 - 2015 and is appealing a tax assessment from an audit by the State of New Jersey for the tax years 2008 - 2011. At December 31, 2019 the tax liability, interest and penalties related to the Refinitiv Contribution is $2.7 million and is included within accounts payable, accrued expenses and other liabilities on the consolidated statement of financial condition. The Company is indemnified by Refinitiv for tax liabilities that were assumed by the Company as a result of the Refinitiv Contribution. An indemnification asset has been recorded for this item. See Note 14 – Related Party Transactions . The above tax positions were recognized using the best estimate of the amount expected to be paid based on available information and assessment of all relevant factors. Due to the uncertainty associated with tax audits, it is possible that at some future date liabilities resulting from these audit could vary significantly from these positions. Nevertheless, based on currently enacted legislation and information currently known to us, the Company believes that the ultimate resolution of these audits will not have a material adverse impact on the Company’s financial condition taken as a whole.

Tax Receivable Agreement

Tax Receivable Agreement	12 Months Ended
	Dec. 31, 2019
Tax Receivable Agreement
Tax Receivable Agreement	10. Tax Receivable Agreement In connection with the Reorganization Transactions, the Corporation entered into the Tax Receivable Agreement with TWM LLC and the Continuing LLC Owners, which provides for the payment by the Corporation to a Continuing LLC Owner of 50% of the amount of U.S. federal, state and local income or franchise tax savings, if any, that the Corporation actually realizes (or in some circumstances is deemed to realize) as a result of (i) increases in the tax basis of TWM LLC’s assets resulting from (a) the purchase of LLC Interests from such Continuing LLC Owner, including with the net proceeds from the IPO, the October 2019 follow-on offering and any future offering or (b) redemptions or exchanges by such Continuing LLC Owner of LLC Interests for shares of Class A common stock or Class B common stock or for cash, as applicable, and (ii) certain other tax benefits related to the Corporation making payments under the Tax Receivable Agreement. Payments under the Tax Receivable Agreement are made annually based on the actual tax savings realized by the Corporation in its previous tax year. In connection with the IPO, the Company recorded an initial liability of $171.4 million related to its projected obligations under the Tax Receivable Agreement with respect to LLC Interests that were purchased by the Corporation using the net proceeds of the IPO. During 2019, the liability increased to $240.8 million primarily due to the purchase of LLC Interests by the Corporation using the net proceeds of the October 2019 follow-on offering as well as additional exchanges of LLC Interests by Continuing LLC Owners during the year ended December 31, 2019 partially offset by changes in tax rates. The Corporation accounts for the income tax effects resulting from taxable redemptions or exchanges of LLC Interests by the Continuing LLC Owners for shares of Class A common stock or Class B common stock or cash, as the case may be, and purchases by the Corporation of LLC Interests from the Continuing LLC Owners by recognizing an increase in deferred tax assets, based on enacted tax rates at the date of each redemption, exchange or purchase, as the case may be. Further, the Corporation evaluates the likelihood that it will realize the benefit represented by the deferred tax asset, and, to the extent that the Corporation estimates that it is more likely than not that it will not realize the benefit, it reduces the carrying amount of the deferred tax asset with a valuation allowance. The impact of any changes in the projected obligations under the Tax Receivable Agreement as a result of changes in the mix of the Company’s earnings, tax legislation and tax rates in various jurisdictions, or other factors that may impact the Corporation’s tax savings, are reflected in income before taxes on the consolidated statement of income in the period in which the change occurs. During the year ended December 31, 2019, the Company recognized a Tax Receivable Agreement liability adjustment of $33.1 million in the consolidated statement of income.

Stockholder's Equity

Stockholder's Equity	12 Months Ended
	Dec. 31, 2019
Stockholder's Equity
Stockholders’ Equity	11. Stockholders’ Equity Initial Public Offering and Reorganization Transactions As described in Note 1 – Organization, in April 2019, the Corporation completed its IPO of 46,000,000 shares of Class A common stock at a public offering price of $27.00, which included 6,000,000 shares of Class A common stock issued pursuant to the underwriters’ option to purchase additional shares of Class A common stock. The Corporation received $1.2 billion in net proceeds, after deducting underwriting discounts and commissions but before deducting offering expenses, which were used to purchase LLC Interests from certain of the Bank Stockholders (and the corresponding shares of common stock were cancelled as described below), at a purchase price per interest equal to the public offering price of $27.00, less the underwriting discounts and commissions payable thereon. In connection with the IPO, the Reorganization Transactions described below were completed. Amendment and Restatement of Certificate of Incorporation On April 3, 2019, the certificate of incorporation of Tradeweb Markets Inc. was amended and restated to, among other things, provide for the authorization of (i) 250,000,000 shares of preferred stock with a par value of $0.00001 per share (ii) 1,000,000,000 shares of Class A common stock with a par value of $0.00001 per share; (iii) 450,000,000 shares of Class B common stock with a par value of $0.00001 per share; (iv) 350,000,000 shares of Class C common stock with a par value of $0.00001 per share; and (v) 300,000,000 shares of Class D common stock with a par value of $0.00001 per share. Each share of Class A common stock and Class C common stock entitles its holder to one vote on all matters presented to the Corporation’s stockholders generally. Each share of Class B common stock and Class D common stock entitles its holder to ten votes on all matters presented to the Corporation’s stockholders generally. The holders of Class C common stock and Class D common stock have no economic interests in the Corporation (where “economic interests” means the right to receive any dividends or distributions, whether cash or stock, in connection with common stock). These attributes are summarized in the following table: Class of Par Votes Economic Class A common stock $ 1 Yes Class B common stock $ 10 Yes Class C common stock $ 1 No Class D common stock $ 10 No Holders of outstanding shares of Class A common stock, Class B common stock, Class C common stock and Class D common stock will vote together as a single class on all matters presented to the Corporation’s stockholders for their vote or approval, except as otherwise required by applicable law. Holders of Class B common stock may from time to time exchange all or a portion of their shares of Class B common stock for newly issued shares of Class A common stock on a one-for-one basis (in which case their shares of Class B common stock will be cancelled on a one-for-one basis upon any such issuance). The Continuing LLC Owners that hold shares of Class D common stock may also from time to time exchange all or a portion of their shares of Class D common stock for newly issued shares of Class C common stock on a one-for-one basis (in which case their shares of Class D common stock will be cancelled on a one-for-one basis upon such issuance). In addition, with respect to each Bank Stockholder that holds shares of Class D common stock, immediately prior to the occurrence of any event that would cause the combined voting power held by such Bank Stockholder to exceed 4.9%, the minimum number of shares of Class D common stock of such Bank Stockholder that would need to convert into shares of Class C common stock such that the combined voting power held by such Bank Stockholder would not exceed 4.9% will automatically convert into shares of Class C common stock. Each share of Class B common stock will automatically convert into one share of Class A common stock and each share of Class D common stock will automatically convert into one share of Class C common stock (i) immediately prior to any sale or other transfer of such share by a holder or its permitted transferees to a non-permitted transferee or (ii) once the Refinitiv Owners and their affiliates together no longer beneficially own a number of shares of common stock and LLC Interests that together entitle them to at least 10% of TWM LLC’s economic interest. Holders of LLC Interests that receive shares of Class C common stock upon any such conversion may continue to elect to have their LLC Interests redeemed for newly issued shares of Class A common stock as described below (in which case their shares of Class C common stock will be cancelled on a one-for-one basis upon such issuance). In addition, the Corporation’s board of directors adopted the Omnibus Equity Plan, under which equity awards may be made in respect of shares of Class A common stock. It also assumed sponsorship of the Option Plan and a PRSU plan formerly sponsored by TWM LLC. See Note 13 – Stock-Based Compensation Plans. Recapitalization of Tradeweb Markets LLC On April 4, 2019, the TWM LLC Agreement was amended and restated to, among other things, (i) provide for the LLC Interests, (ii) exchange all of the then existing membership interests in TWM LLC for LLC Interests and (iii) appoint the Corporation as the sole manager of TWM LLC. All of the shares of TWM LLC outstanding prior to the Reorganization Transactions were exchanged for 222,222,197 LLC Interests. TWM LLC’s outstanding shares prior to the Reorganization Transactions consisted of the following classes of shares: Shares Class A 146,333 Class C 447 Class P (A) 6,887 Class P (C) 2 Class P-1(A) 6,094 Class P-1 (C) 232 The TWM LLC Agreement requires that TWM LLC at all times maintain (i) a one-to-one ratio between the number of shares of Class A common stock and Class B common stock issued by the Corporation and the number of LLC Interests owned by the Corporation and (ii) a one-to-one ratio between the number of shares of Class C common stock and Class D common stock issued by the Corporation and the number of LLC Interests owned by the holders of such Class C common stock and Class D common stock. LLC Interests held by Continuing LLC Owners are redeemable in accordance with the TWM LLC Agreement, at the election of such holders, for newly issued shares of Class A common stock or Class B common stock, as the case may be, on a one-for-one basis (and such holders’ shares of Class C common stock or Class D common stock, as the case may be, will be cancelled on a one-for-one basis upon any such issuance). In the event of such election by a Continuing LLC Owner, the Corporation may, at its option, effect a direct exchange of Class A common stock or Class B common stock for such LLC Interests of such Continuing LLC Owner in lieu of such redemption. In addition, the Corporation’s board of directors may, at its option, instead of the foregoing redemptions or exchanges of LLC Interests, cause the Corporation to make a cash payment equal to the volume weighted average market price of one share of Class A common stock for each LLC Interest redeemed or exchanged (subject to customary adjustments, including for stock splits, stock dividends and reclassifications) in accordance with the terms of the TWM LLC Agreement. Issuance and Cancellation of Common Stock · As a result of the Refinitiv Contribution, the Corporation received 96,933,192 LLC Interests and the Refinitiv Direct Owner received 96,933,192 shares of Class B common stock. · The Corporation issued 20,000,000 shares of Class C common stock and 105,289,005 shares of Class D common stock to the Original LLC Owners that received LLC Interests on a one-to-one basis with the number of LLC Interests they owned immediately following the amendment and restatement of the TWM LLC Agreement for nominal consideration (the Corporation subsequently cancelled 9,993,731 shares of such Class C common stock and 36,006,269 shares of such Class D common stock in connection with the Corporation’s purchase of LLC Interests from certain of the Bank Stockholders using the net proceeds of the IPO). Following the completion of the Reorganization Transactions, including the IPO and the application of the proceeds therefrom as described above, (i) the investors in the IPO collectively owned 46,000,000 shares of Class A common, representing 2.7% of the combined voting power of all of the Corporation’s common stock and, through the Corporation’s ownership of LLC Interests, 20.7% of the economic interest in TWM LLC; (ii) the Refinitiv Direct Owner owned 96,933,192 shares of Class B common stock, representing 56.4% of the combined voting power of all of the Corporation’s common stock and, through the Corporation’s ownership of LLC Interests, 43.6% of the economic interest in TWM LLC; (iii) the Refinitiv LLC Owner owned 22,988,329 shares of Class D common stock, representing 13.4% of the combined voting power of all of the Corporation’s common stock, and 22,988,329 LLC Interests, representing 10.3% of the economic interest in TWM LLC, (iv) the Continuing LLC Owners (other than the Refinitiv LLC Owner) collectively owned 10,006,269 shares of Class C common stock and 46,294,407 shares of Class D common stock, representing 27.5% of the combined voting power of all of the Corporation’s common stock, and 56,300,676 LLC Interests, representing 25.3% of the economic interest in TWM LLC; and (v) the Corporation owned 142,933,192 LLC Interests, representing 64.3% of the economic interest in TWM LLC. October 2019 Follow-On Offering In the fourth quarter of 2019, Tradeweb Markets Inc. completed an underwritten follow-on offering of 19,881,059 shares of Class A Common stock at a public offering price of $42.00 per share, which included 2,593,181 shares of Class A common stock issued pursuant to the underwriters’ option to purchase additional shares of Class A common stock. Tradeweb Markets Inc. received net proceeds of $810.0 million, after deducting underwriting discounts and commissions but before deducting estimated offering expenses, which were used to purchase (i) 19,835,666 issued and outstanding LLC Interests from certain of the Bank Stockholders and certain of our executive officers (and the corresponding shares of Class C common stock and/or Class D common stock held by such holders were cancelled) and (ii) 45,393 issued and outstanding shares of Class A common stock from certain of our executive officers (which shares of) and (ii) 45,393 issued and outstanding shares of Class A common stock from certain of our executive officers (which shares of Class A common stock were cancelled), at a purchase price per interest and share equal to the public offering price of $42.00, less the underwriting discounts and commissions payable thereon. Redemptions and Exchanges of LLC Interests In addition to the IPO and the October 2019 follow-on offering transactions described above, during the year ended December 31, 2019, certain Continuing LLC Owners exercised their redemption rights under the TWM LLC Agreement, pursuant to which 271,184 LLC Interests were exchanged for 271,184 newly-issued shares of Class A common stock. Simultaneously, and in connection with these exchanges, 271,184 shares of Class D common stock were surrendered by these Continuing LLC Owners and cancelled. Additionally, in connection with these exchanges, Tradeweb Markets Inc. received 271,184 LLC Interests, increasing its total ownership interest in TWM LLC. As a result of the Reorganization Transactions, the IPO, the October 2019 follow-on offering and other exchanges and equity activity, as of December 31, 2019: " The public investors collectively owned 66,408,328 shares of our Class A common stock, representing 4.3% of the combined voting power of Tradeweb Markets Inc.’s issued and outstanding common stock and indirectly, through Tradeweb Markets Inc., owned 29.8% of the economic interest in TWM LLC; " Refinitiv collectively owned 96,933,192 shares of our Class B common stock and 22,988,329 shares of our Class D common stock, representing 77.2% of the combined voting power of Tradeweb Markets Inc.’s issued and outstanding common stock and directly and indirectly, through Tradeweb Markets Inc., owned 53.9% of the economic interest in TWM LLC; " The Bank Stockholders that continue to own LLC Interests collectively owned 8,328,983 shares of our Class C common stock and 27,662,354 shares of our Class D common stock, representing 18.4% of the combined voting power of Tradeweb Markets Inc.’s issued and outstanding common stock and directly and indirectly, through Tradeweb Markets Inc., owned 16.2% of the economic interest in TWM LLC.

Non-Controlling Interests

Non-Controlling Interests	12 Months Ended
	Dec. 31, 2019
Non-Controlling Interests
Non-Controlling Interests	12. Non-Controlling Interests In connection with the Reorganization Transactions, Tradeweb Markets Inc. became the sole manager of TWM LLC and, as a result of this control, and because Tradeweb Markets Inc. has a substantial financial interest in TWM LLC, consolidates the financial results of TWM LLC into its consolidated financial statements. The non-controlling interests balance reported on the consolidated statements of financial condition represents the economic interests of TWM LLC held by the holders of LLC Interests other than Tradeweb Markets Inc. Income or loss is attributed to the non-controlling interests based on the relative ownership percentages of LLC Interests held during the period by Tradeweb Markets Inc. and the other holders of LLC Interests. The following table summarizes the ownership interest in Tradeweb Markets LLC: December 31, 2019 LLC Ownership Interests % Number of LLC Interests held by Tradeweb Markets Inc. 163,341,520 Number of LLC Interests held by non-controlling interests 59,182,155 Total LLC Interests outstanding 222,523,675 LLC Interests held by the Continuing LLC Owners are redeemable in accordance with the TWM LLC Agreement at the election of the members for shares of Class A common stock or Class B common stock, on a one-for-one basis or, at the Company's option, a cash payment in accordance with the terms of the TWM LLC Agreement. See Note 11 – Stockholders’ Equity. The following table summarizes the impact on equity due to changes in the Corporation’s ownership interest in TWM LLC (in thousands): Successor Year Ended December 31, Net Income Attributable to Tradeweb Markets Inc. and Transfers (to) from the Non-Controlling Interests 2019 Net income attributable to Tradeweb Markets Inc. $ 83,769 Transfers (to) from non-controlling interests: Allocation of equity to non-controlling interests arising from the reorganization transactions and IPO (1,607,529) Change in non-controlling interests as a result of the October 2019 follow-on offering and other ownership changes 402,227 Net transfers (to) from non-controlling interests (1,205,302) Change from net income attributable to Tradeweb Markets Inc. and transfers (to) from non-controlling interests $ (1,121,533)

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2019
Stock-Based Compensation Plans
Stock-Based Compensation Plans	13. Stock-Based Compensation Plans Under the Omnibus Equity Plan, the Company is authorized to issue up to 8,841,864 new shares of the Company’s common stock to employees, officers and non-employee directors. Under this plan, the Company may grant awards based on shares of its common stock, including performance-based restricted share units (“PRSUs”), stock options, restricted stock units (“RSUs”) and dividend equivalent rights. The awards may have performance-based and time-based vesting conditions. Stock options have a maximum contractual term of 10 years. PRSUs (Equity-Settled) PRSUs are promises to issue actual shares of Class A common stock at the end of a three-year cliff vesting period. The fair value of the equity-settled PRSUs is calculated on the grant date using the stock price of the Class A common stock. The number of shares a participant will receive upon vesting is determined by a performance modifier, which is adjusted as a result of the financial performance of the Company in the grant year. The performance modifier can vary between 0% (minimum) and 200% (maximum) of the target (100%) award amount. On December 31, 2018, certain PRSUs, which were previously cash-settled, were converted to equity-settled PRSUs. No equity-settled PRSUs were granted by the Company prior to December 31, 2018. The conversion was at fair value, using a unit price consistent with the share price of the Company, and as a result of the impact of the performance modifier on PRSUs value. 1,033.2 cash-settled PRSUs were converted into the equivalent value of 2,000,384 equity-settled PRSUs, adjusted retroactively for the Recapitalization of TWM LLC described in Note 11 – Stockholders’ Equity, having vesting terms similar to the cash-settled PRSUs. As a result of the modification, which impacted 54 employees, the Company reclassified $19.1 million from employee equity compensation payable to members’ capital in the December 31, 2018 statement of financial condition. A summary of the Company’s outstanding equity-settled PRSUs is presented below: Weighted Average Equity-Settled Grant-Date PRSUs Fair Value Equity-settled PRSUs outstanding at December 31, 2018 2,000,384 $ 9.53 Grants 781,026 $ 21.08 Vests — $ — Performance adjustment 762,326 $ 21.08 Forfeitures (53,070) $ 13.48 Equity-settled PRSUs outstanding at December 31, 2019 3,490,666 $ 14.59 The following table shows a summary of equity-settled PRSU activity during the year ended December 31, 2019 (in thousands): Successor Year Ended December 31, 2019 Equity-settled PRSU compensation expense $ 25,392 Income tax benefit $ (4,781) PRSUs (Cash-Settled) The Company previously granted cash-settled PRSUs, some of which are still outstanding and are accounted for as liability awards. The Company measures the cost of employee services received in exchange for the award based on the fair value of the Company and the value of accumulated dividend rights associated with each award. The fair value of that award is remeasured subsequently at each reporting date through to settlement. Changes in the award's fair value during the requisite service period are recognized as compensation cost over that period. A summary of the Company’s outstanding cash-settled PRSUs is presented below: Weighted Cash-Settled Average PRSUs Fair Value Cash-settled PRSUs outstanding at December 31, 2018 522 $ 34,221 Grants — $ — Vests (1) (507) $ 33,842 Forfeitures — $ — Cash-settled PRSUs outstanding at December 31, 2019 15 $ 94,997 (1) The total fair value of cash-settled PRSUs vested was $17.2 million for the year ended December 31, 2019. Options Prior to the IPO, the Company awarded options to management and other employees under the Option Plan. Each option award vests one half based solely on the passage of time and one half only if the Company achieves certain performance targets. The time vesting portion of the options has a four-year graded vesting schedule, with accelerated vesting for time-based options with vesting dates of January 1, 2021 and 2022 upon the completion of an initial public offering. The Company can elect to net-settle exercised options by reducing the shares of Class A common stock to be issued upon such exercise by the number of shares of Class A common stock having a fair market value on the date of exercise equal to the aggregate option price and withholding taxes payable in respect of the number of options exercised. The Company can also elect, upon exercise, to reduce the shares to be issued by the number of shares having a fair market value on the date of exercise equal to employee payroll taxes. The Company may then pay these employee payroll taxes from the Company’s cash. In accounting for options issued under the Option Plan, or which may be issued under the Omnibus Equity Plan in the future, the Company measures and recognizes compensation expense for all awards based on their estimated fair values measured as of the grant date. Options issued under the Option Plan are exercisable following the closing of an initial public offering or during a 15‑day period following a change in control of the Company (and certain other sales of equity by the Company’s shareholders). Costs related to these options are recognized as an expense in the consolidated statements of income over the requisite service period, when exercisability is considered probable, with an offsetting increase to additional paid-in capital. As a result, expense recognition commenced upon the completion of the IPO, with $18.9 million recognized as compensation expense related to options issued under the Option Plan immediately upon the completion of the IPO. The fair value of options is calculated on the grant date using the Black-Scholes model. The significant assumptions used to estimate the fair value as of grant date of the options awarded prior to the IPO did not reflect changes that would have occurred to these assumptions as a result of the IPO. A summary of the Company’s outstanding options is presented below: Weighted Average Grant-Date Options Fair Value Options outstanding at December 31, 2018 18,091,793 $ 1.85 Grants 886,115 $ 8.83 Exercises (984,585) $ 1.80 Forfeitures and adjustments (253,579) $ 2.67 Options outstanding at December 31, 2019 17,739,744 $ 2.19 Vested options outstanding at December 31, 2019 $ The total intrinsic value of options exercised in 2019 was $21.3 million. At December 31, 2018, no options were vested or exercisable. The following table shows a summary options activity during the year ended December 31, 2019 (in thousands): Successor Year Ended December 31, 2019 Options compensation expense $ 24,432 Income tax benefit $ (8,556) The significant assumptions used to estimate the fair value of the options as of the grant date were as follows: Weighted Average Expected Life (years) 5.7 Weighted Average Risk-Free Interest Rate 2.9 % Weighted Average Expected Volatility 20.0 % Weighted Average Expected Dividend Yield 3.9 % Weighted Average Share Price $ 21.62 Weighted Average Exercise Price $ 21.62 Compensation Expense The Company records stock-based compensation expense for employees and directors in the consolidated statements of income. The total stock-based compensation expense for the year ended December 31, 2019, the 2018 Successor Period, the 2018 Predecessor Period and the year ended December 31, 2017 is $50.7 million, $9.4 million, $15.9 million and $26.1 million, respectively. As of December 31, 2019, total unrecognized compensation expense related to unvested stock-based compensation arrangements and the expected recognition period are as follows (dollars in thousands): Cash-Settled Equity-Settled PRSUs PRSUs Options Total unrecognized compensation cost $ 383 $ 31,283 $ 4,068 Weighted-average recognition period 1.0 years 1.7 years 2.8 years

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions
Related Party Transactions	14. Related Party Transactions The Company enters into transactions with its affiliates from time to time which are considered to be related party transactions. Prior to the Reorganization Transactions, the Bank Stockholders were collectively considered to be related parties of the Company. As a result of the Reorganization Transactions, they are no longer considered to be related parties. As a result, the related party transactions listed below include transactions with the Bank Stockholders or their respective affiliates for pre-IPO periods only. At December 31, 2019 and 2018, the following balances with such affiliates were included in the consolidated statements of financial condition in the following line items (in thousands): Successor Successor December 31, 2019 December 31, 2018 Cash and cash equivalents $ — $ 283,790 Receivables from brokers and dealers and clearing organizations — 3,332 Deposits with clearing organizations — 500 Accounts receivable — 40,730 Receivable from affiliates 2,525 3,243 Other assets — 9 Payable to brokers and dealers and clearing organizations — 2,404 Deferred revenue 4,733 9,151 Payable to affiliates 1,506 5,009 The following balances with such affiliates were included in the consolidated statements of income in the following line items (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 January 1, 2018 Year Ended December 31, to to December 31, 2019 December 31, 2018 September 30, 2018 2017 Revenue: Transaction fees (1) $ 59,643 $ 59,259 $ 159,663 $ 151,695 Subscription fees (1) 5,670 5,718 16,627 37,426 Commissions (1) 16,186 12,401 34,944 43,315 Refinitiv market data fees (2) 55,635 13,467 36,851 50,125 Operating Income: (3) Net interest income (expense) 858 17 (415) Shared Services Fees (4) : Technology and communications 2,960 740 2,220 2,960 General and administrative 430 180 539 719 Occupancy 481 155 466 621 (1) For pre-IPO periods, represents fees and commissions from affiliates of the Bank Stockholders. (2) The Company maintains a market data license agreement with Refinitiv (TR in the predecessor period). Under the agreement, the Company delivers to Refinitiv certain market data feeds which Refinitiv redistributes to its customers. The Company earns license fees and royalties for these feeds. (3) For pre-IPO periods, represents interest income from money market funds invested with and savings accounts deposited with affiliates of the Bank Stockholders. (4) The Company maintains a shared services agreement with Refinitiv (TR in the predecessor period). Under the terms of the agreement, Refinitiv provides the Company with certain real estate, payroll, benefits administration, insurance, content, financial reporting and tax support. The Company reimburses affiliates of Refinitiv (TR in the predecessor period) for expenses paid on behalf of the Company for various services including salaries and bonuses, marketing, professional fees, communications, data costs and certain other administrative services. For the year ended December 31, 2019, the 2018 Successor Period, the 2018 Predecessor Period and the year ended December 31, 2017, the Company reimbursed such affiliates approximately $6.7 million, $3.8 million, $28.7 million, and $38.4 million, respectively, for these expenses. The Company is indemnified by Refinitiv for any tax liabilities that existed in the entity contributed by Refinitiv as a result of the Refinitiv Contribution. $2.7 million is included in other assets on the December 31, 2019 consolidated statement of financial condition related to this indemnification. The Company engaged Blackstone Advisory Partners L.P., an affiliate of Blackstone, to provide certain financial consulting services in connection with the IPO and the October 2019 follow-on offering for a fee of $1.0 million and $0.5 million, respectively, which fee, with respect to the October 2019 follow-on offering, was reimbursed by the underwriters of the October 2019 follow-on offering. $1.5 million is included in additional paid-in capital on the December 31, 2019 consolidated statement of financial condition related to these offering costs. During 2014, the Company issued Class A Shares and unvested Class P-1(A) Shares to some of the Bank Stockholders as a result of a $120.0 million capital contribution. In connection with this investment, employees invested $5.3 million in the Company and were issued Class C Shares and unvested Class P-1(C) Shares. Certain Class P-1(A) Shares and Class P-1(C) Shares vested on July 31, 2018, based on a formula determined by the Company’s new credit platforms’ revenues and any remaining unvested Class P-1(A) Shares and Class P-1(C) Shares were cancelled and as a result no contingent consideration has been recognized related to these shares subsequent to that date. The Company recognized contingent consideration for the 2018 Predecessor Period and for the year ended December 31, 2017 of $26.8 million and $58.5 million, respectively, relating to these shares, which is included in net revenue on the consolidated statements of income.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2019
Fair Value of Financial Instruments
Fair Value of Financial Instruments	15. Fair Value of Financial Instruments Certain financial instruments that are carried on the consolidated statements of financial condition are carried at amounts that approximate fair value. These instruments include receivable from/payable to brokers and dealers and clearing organizations, deposits with clearing organizations and accounts receivable. The Company's money market funds are classified within level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. The Company has no instruments that are classified within level 2 or level 3 of the fair value hierarchy. The fair value measurements are as follows (in thousands): Quoted Prices in active Markets Significant Significant for Identical Observable Unobservable Assets Inputs Inputs Successor (Level 1) (Level 2) (Level 3) Total As of December 31, 2019 Assets Money market funds $ 219,158 $ — $ — $ 219,158 $ 219,158 $ — $ — $ 219,158 As of December 31, 2018 Assets Money market funds $ 127,927 $ — $ — $ 127,927 $ 127,927 $ — $ — $ 127,927

Credit Risk

Credit Risk	12 Months Ended
	Dec. 31, 2019
Credit Risk
Credit Risk	16. Credit Risk The Company may be exposed to credit risk regarding its receivables, which are primarily receivables from financial institutions, including investment managers and broker-dealers. At December 31, 2019 and December 31, 2018, the Company established an allowance for doubtful accounts of $0.2 million and $1.2 million, respectively, with regard to these receivables. In the normal course of business the Company, as agent, executes transactions with, and on behalf of, other broker-dealers. If the agency transactions do not settle because of failure to perform by either counterparty, the Company may be obligated to discharge the obligation of the non-performing party and, as a result, may incur a loss if the market value of the security is different from the contract amount of the transaction. A substantial number of the Company's transactions are collateralized and executed with, and on behalf of, a limited number of broker-dealers. The Company's exposure to credit risk associated with the nonperformance of these clients in fulfilling their contractual obligations pursuant to securities transactions can be directly impacted by volatile trading markets which may impair the clients' ability to satisfy their obligations to the Company. From time to time, the Company enters into agreements to repurchase to facilitate the clearance of securities. Credit exposure related to these agreements to repurchase, including the risk related to a decline in market value of collateral (pledged or received), is managed by entering into agreements to repurchase with overnight or short-term maturity dates and only entering into repurchase transactions with netting members of the Fixed Income Clearing Corporation (“FICC”). The FICC requires dealer netting members to maintain a minimum of $25 million in equity capital and $10 million in excess net capital. The FICC operates a continuous net settlement system, whereby as trades are submitted and compared the FICC becomes the counterparty. The FICC also marks to market collateral on a daily basis, requiring member firms to pay or receive margin amounts as part of their daily funds settlement. The Company does not expect nonperformance by counterparties in the above situations. However, the Company's policy is to monitor its market exposure and counterparty risk. In addition, the Company has a policy of reviewing, as considered necessary, the credit standing of each counterparty with which it conducts business.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies
Commitments and Contingencies	17. Commitments and Contingencies In the normal course of business, the Company enters into user agreements with its dealers which provide the dealers with indemnification from third parties in the event that the electronic marketplaces of the Company infringe upon the intellectual property or other proprietary right of a third party. The Company's exposure under these user agreements is unknown as this would involve estimating future claims against the Company which have not yet occurred. However, based on its experience, the Company expects the risk of a material loss to be remote. The Company has been named as a defendant, along with other financial institutions, in antitrust class actions (consolidated into two actions) relating to trading practices in United States Treasury securities auctions. The Company has filed a motion to dismiss the actions, believes it has substantial defenses to the other plaintiff's claims and intends to defend itself vigorously. Additionally, the Company was dismissed from a class action relating to an interest rate swaps matter in 2017, but that matter continues against the remaining defendant financial institutions. The Company is a co-defendant in a matter relating to the distribution of financial strength ratings over the Company's trading platform to one of its customers. The matter alleges that while certain business units of the client were licensed to receive the data via the Company's platform, the data was also distributed without authorization to certain end clients of the customer. The plaintiff claims to have suffered approximately $80 million in damages and also seeks punitive damages, attorneys' fees and costs. In September 2019, the Court dismissed some, but not all, of plaintiff’s claims, and rejected plaintiff’s damages theory on which it relied to support its claims for approximately $80 million in damages for its breach of contract claim. The defendants are still challenging with pre-trial motions whether the plaintiff’s $80 million damage theory is viable with respect to its tort claims, and the plaintiff has in parallel offered an alternative theory quantifying its damages at $4 million to $8 million, which it will pursue if the $80 million theory is disallowed. The matter is now scheduled for trial in October 2020 with respect to the tort claims that survived. The Company intends to continue to vigorously defend what the Company believes to be meritless claims. The Company records its best estimate of a loss, including estimated defense costs, when the loss is considered probable and the amount of such loss can be reasonably estimated. Based on its experience, the Company believes that the amount of damages claimed in a legal proceeding is not a meaningful indicator of the potential liability. At this time, the Company cannot reasonably predict the timing or outcomes of, or estimate the amount of loss, or range of loss, if any, related to its pending legal proceedings, including the matters described above, and therefore does not have any contingency reserves established for any of these matters. Revolving Credit Facility On April 8, 2019, the Company entered into a five year, $500 million senior secured revolving credit facility (“Credit Facility”) with a syndicate of banks. The Credit Facility provides additional borrowing capacity to be used to fund ongoing working capital needs, letters of credit and for general corporate purposes, including potential future acquisitions and expansions. On November 7, 2019, TWM LLC entered into an amendment to the Revolving Credit Facility among TWM LLC and the lenders party thereto, which revised the Revolving Credit Facility to permit the pending LSEG Transaction. The amendment did not otherwise impact the terms of the Revolving Credit Facility and did not impact the amount of borrowings available to TWM LLC under the Revolving Credit Facility. Under the terms of the credit agreement that governs the Credit Facility, borrowings under the Credit Facility bear interest at a rate equal to, at the Company’s option, either (a) a base rate equal to the greatest of (i) the administrative agent’s prime rate, (ii) the federal funds effective rate plus ½ of 1.0% and (iii) one month LIBOR plus 1.0%, in each case plus 0.75%, or (b) LIBOR plus 1.75%, subject to a 0.00% floor. The credit agreement also includes a commitment fee of 0.25% for available but unborrowed amounts and other administrative fees that are payable quarterly. The Credit Facility is available until April 2024, provided the Company is in compliance with all covenants. Financial covenant requirements include maintaining minimum ratios related to interest coverage and leverage. As of December 31, 2019, there were no amounts outstanding under the Credit Facility.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share
Earnings Per Share	18. Earnings Per Share In April 2019, the Company completed the Reorganization Transactions and the IPO, which, among other things, resulted in the Corporation becoming the successor of TWM LLC for financial reporting purposes. As a result, earnings per share information for the pre-IPO period is not comparable to earnings per share information for the post-IPO period. Thus, earnings per share information is being presented separately for the pre-IPO and post-IPO periods. The following table summarizes the basic and diluted earnings per share calculations for Tradeweb Markets LLC (pre-IPO period): Successor Successor Predecessor Predecessor Three Months Ended October 1, 2018 to January 1, 2018 to Year Ended March 31, December 31, September 30, December 31, EPS: Pre-IPO net income attributable to Tradeweb Markets LLC (1) 2019 2018 2018 2017 (in thousands, except share and per share amounts) Numerator: Pre-IPO net income attributable to Tradeweb Markets LLC $ 42,352 $ 29,307 $ 130,160 $ 83,648 Denominator: Weighted average LLC Interests outstanding - Basic 222,222,197 222,221,628 215,365,920 212,568,635 Dilutive effect of equity-settled PRSUs 1,098,260 22,223 — — Weighted average LLC Interests outstanding - Diluted 223,320,457 222,243,851 215,365,920 212,568,635 Earnings per share - Basic $ 0.19 $ 0.13 $ 0.60 $ 0.39 Earnings per share - Diluted $ 0.19 $ 0.13 $ 0.60 $ 0.39 (1) Earnings per share and weighted average shares outstanding for the pre-IPO periods have been computed to give effect to the Reorganization Transactions, including the amendment and restatement of the TWM LLC Agreement to, among other things, (i) provide for LLC Interests and (ii) exchange all of the then existing membership interests in TWM LLC for LLC interests. The following table summarizes the basic and diluted earnings per share calculations for Tradeweb Markets Inc. (post-IPO period): Successor Nine Months Ended EPS: Post-IPO net income attributable to Tradeweb Markets Inc. December 31, (in thousands, except share and per share amounts) 2019 Numerator: Post-IPO net income attributable to Tradeweb Markets Inc. $ 83,769 Denominator: Weighted average shares of Class A and Class B common stock outstanding - Basic 148,013,274 Dilutive effect of equity-settled PRSUs 2,464,137 Dilutive effect of options 6,062,835 Weighted average shares of Class A and Class B common stock outstanding - Diluted 156,540,246 Earnings per share - Basic $ 0.57 Earnings per share - Diluted $ 0.54 For the year ended December 31, 2019, there were approximately 128,125 average shares underlying equity-settled PRSUs and options that were anti-dilutive. As a result, these shares, which are still outstanding, were excluded from the computation of diluted earnings per share. For the 2018 Predecessor Period, there were approximately 5,444,566 average shares related to the contingent consideration payable that were anti-dilutive and thus excluded from the computation of diluted earnings per share. LLC Interests held by the Continuing LLC Owners are redeemable in accordance with the TWM LLC Agreement, at the election of such holders, for shares of Class A or Class B common stock of Tradeweb Markets Inc. After evaluating the potential dilutive effect under the if-converted method, the 59,182,155 LLC Interests for the assumed exchange of non-controlling interests were determined to be anti-dilutive and thus were excluded from the computation of diluted earnings per share for the post-IPO periods. Shares of Class C and Class D common stock do not have economic rights in Tradeweb Markets Inc. and, therefore, are not included in the calculation of basic earnings per share and are not participating securities for purposes of the computation of diluted earnings per share.

Regulatory Capital Requirements

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2019
Regulatory Capital Requirements
Regulatory Capital Requirements	19. Regulatory Capital Requirements TWL, DW and TWD are subject to the Uniform Net Capital Rule 15c3‑1 under the Securities Exchange Act of 1934. TEL is subject to certain financial resource requirements with the FCA in the UK, TWJ is subject to certain financial resource requirements with the FCA in Japan and TWEU is subject to certain finance resource requirements with the AFM in the Netherlands. At December 31, 2019 and 2018, the regulatory capital requirements and regulatory capital for TWL, DW, TWD, TEL, TWJ and TWEU are as follows (in thousands): As of December 31, 2019 TWL DW TWD TEL TWJ TWEU Regulatory Capital $ 42,317 $ 52,016 $ 33,807 $ 49,611 $ 11,851 $ 6,217 Regulatory Capital Requirement 2,396 2,026 664 21,856 8,565 1,701 Excess Regulatory Capital $ 39,921 $ 49,990 $ 33,143 $ 27,755 $ 3,286 $ 4,516 As of December 31, 2018 TWL DW TWD TEL TWJ Regulatory Capital $ 18,986 $ 41,164 $ 24,042 $ 46,157 $ 10,592 Regulatory Capital Requirement 2,698 1,803 599 17,493 3,413 Excess Regulatory Capital $ 16,288 $ 39,361 $ 23,443 $ 28,664 $ 7,179 As SEFs, TW SEF and DW SEF are required to maintain adequate financial resources and liquid financial assets in accordance with CFTC regulations. The required and maintained financial resources and liquid financial assets at December 31, 2019 and 2018 are as follows (in thousands): As of December 31, 2019 As of December 31, 2018 TW SEF DW SEF TW SEF DW SEF Financial Resources $ 21,303 $ 13,707 $ 31,232 $ 17,837 Required Financial Resources 10,500 5,505 10,500 5,169 Excess Financial Resources $ 10,803 $ 8,202 $ 20,732 $ 12,668 Liquid Financial Assets $ 18,168 $ 7,583 $ 16,662 $ 11,888 Required Liquid Financial Assets 5,250 2,753 5,250 2,585 Excess Liquid Financial Assets $ 12,918 $ 4,830 $ 11,412 $ 9,303

Business Segment and Geographic

Business Segment and Geographic Information	12 Months Ended
	Dec. 31, 2019
Business Segment and Geographic Information
Business Segment and Geographic Information	20. Business Segment and Geographic Information The Company operates electronic marketplaces for the trading of products across the rates, credit, equities and money markets asset classes and provides related pre-trade and post-trade services. The Company’s operations constitute a single business segment because of the integrated nature of these marketplaces and services. Information regarding revenue by client sector is as follows (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Net revenue: Institutional $ 453,379 $ 103,971 $ 301,918 $ 318,038 Wholesale 171,096 38,153 99,028 118,451 Retail 80,368 19,780 57,766 70,857 Market Data 70,723 16,733 47,059 55,622 Contingent consideration — — (26,830) (58,520) Net revenue 775,566 178,637 478,941 504,448 Operating expenses 585,747 146,702 338,607 415,356 Operating income $ 189,819 $ 31,935 $ 140,334 $ 89,092 The Company operates in the U.S. and internationally, primarily in the Europe and Asia regions. Revenues are attributed to geographic area based on the jurisdiction where the underlying transactions take place. The results by geographic region are not meaningful in understanding the Company's business. Long-lived assets are attributed to the geographic area based on the location of the particular subsidiary. The following table provides a breakdown of revenue by geographic area for the year ended December 31, 2019, the 2018 Successor Period, the 2018 Predecessor Period and the year ended December 31, 2017 (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Net Revenue: U.S. $ 497,316 $ 115,907 $ 324,304 $ 385,176 International 278,250 62,730 181,467 177,792 Gross revenue 775,566 178,637 505,771 562,968 Contingent consideration — — (26,830) (58,520) Total $ 775,566 $ 178,637 $ 478,941 $ 504,448 The following table provides information on the attribution of long-lived assets by geographic area (in thousands): Successor Successor December 31, December 31, 2019 2018 Long-lived assets U.S. $ 4,200,133 $ 4,276,568 International 14,100 7,787 Total $ 4,214,233 $ 4,284,355

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Results of Operations (Unaudited)
Quarterly Results of Operations (Unaudited)	21. Quarterly Results of Operations (Unaudited) The following tables set forth certain unaudited financial data for the Company’s quarterly operations in 2019 and 2018. The following information has been prepared on the same basis as the annual information presented elsewhere in this report and, in the opinion of management, includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the information for the quarterly periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Tradeweb Markets Inc. (post-IPO) Tradeweb Markets LLC (pre-IPO) Successor Successor Successor Successor Successor Predecessor Predecessor Predecessor Three Months Ended December 31, September 30, June 30, March 31, December 31, September 30, June 30, March 31, 2019 2019 2019 2019 2018 2018 2018 2018 Revenues (in thousands, except share and per share data) Transaction fees $ 104,245 $ 112,746 $ 103,952 $ 102,640 $ 97,130 $ 92,582 $ 91,030 $ 90,139 Subscription fees 34,333 35,387 34,566 34,445 33,052 33,157 37,647 36,326 Commissions 41,165 37,590 36,413 34,197 32,840 24,394 27,553 27,883 Refinitiv market data fees 15,383 13,251 13,385 13,616 13,467 12,533 12,081 12,237 Other 2,182 2,007 2,169 1,894 2,148 2,587 2,704 2,918 Gross revenue 197,308 200,981 190,485 186,792 178,637 165,253 171,015 169,503 Contingent consideration — — — — — 2,537 (19,297) (10,070) Net revenue 197,308 200,981 190,485 186,792 178,637 167,790 151,718 159,433 Expenses Employee compensation and benefits 76,545 79,644 95,995 77,273 80,436 69,076 68,407 71,570 Depreciation and amortization 36,402 35,133 34,292 33,503 33,020 16,362 16,178 16,268 Technology and communications 10,199 9,527 9,519 10,040 9,907 9,112 9,023 8,463 General and administrative 8,999 7,507 9,365 9,089 11,837 9,386 7,153 6,517 Professional fees 7,048 7,272 6,738 6,971 8,194 7,546 7,276 5,538 Occupancy 3,786 3,640 3,621 3,639 3,308 3,491 3,519 3,722 Total expenses 142,979 142,723 159,530 140,515 146,702 114,973 111,556 112,078 Operating income 54,329 58,258 30,955 46,277 31,935 52,817 40,162 47,355 Tax receivable agreement liability adjustment 33,134 — — — — — — — Net interest income 704 636 175 858 787 673 582 471 Income before taxes 88,167 58,894 31,130 47,135 32,722 53,490 40,744 47,826 Provision for income taxes (30,889) (10,316) (6,314) (4,783) (3,415) (7,535) (1,847) (2,518) Net income $ 57,278 $ 48,578 $ 24,816 $ 42,352 $ 29,307 $ 45,955 $ 38,897 $ 45,308 Net income attributable to non-controlling interests $ 15,949 $ 18,966 $ 11,988 Net income attributable to Tradeweb Markets Inc. $ 41,329 $ 29,612 $ 12,828 Earnings per share (1) Basic $ $ $ $ $ $ $ $ Diluted $ $ $ $ $ $ $ $ Weighted average shares outstanding Basic 157,950,550 142,935,206 142,933,192 222,222,197 222,221,628 219,165,997 213,435,314 213,435,321 Diluted 167,323,520 151,362,643 150,847,183 223,320,457 222,243,851 219,165,997 213,435,314 213,435,321 (1) In April 2019, the Company completed the Reorganization Transactions and the IPO, which, among other things, resulted in Tradeweb Markets Inc. becoming the successor of Tradeweb Markets LLC for financial reporting purposes. As a result, earnings per share information for the pre-IPO period is not comparable to the earnings per share information for the post-IPO period. See Note 18 — Earnings Per Share for additional information. Earnings per share for quarterly periods are based on the weighted average common shares outstanding in individual quarters; thus, the sum of earnings per share of the quarters may not equal the amounts reported for the full year.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events
Subsequent Events	22. Subsequent Even On February 11, 2020, the board of directors of Tradeweb Markets Inc. declared a cash dividend of $0.08 per share of Class A common stock and Class B common stock for the first quarter of 2020. This dividend will be payable on March 16, 2020 to stockholders of record as of March 2, 2020.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Significant Accounting Policies
Basis of Accounting	Basis of Accounting The consolidated financial statements have been presented in conformity with accounting principles generally accepted in the United States of America.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates and the difference may be material to the consolidated financial statements.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consists of cash and highly liquid investments (such as short-term money market instruments) with original maturities of less than three months.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The Company continually monitors collections and payments from its clients and maintains an allowance for doubtful accounts. The allowance for doubtful accounts is based upon the historical collection experience and specific collection issues that have been identified. Additions, if any, to the allowance for doubtful accounts are charged to bad debt expense, which is included in general and administrative expenses on the consolidated statements of income.
Receivable from and Payable to Brokers and Dealers and Clearing Organizations	Receivable from and Payable to Brokers and Dealers and Clearing Organizations Receivable from and payable to brokers and dealers and clearing organizations consists of proceeds from transactions which failed to settle due to the inability of a transaction party to deliver or receive the transacted security. These securities transactions are generally collateralized by those securities. At times, transactions executed on the Company’s wholesale platform fail to settle due to the inability of a transaction party to deliver or receive the transacted security. Until the failed transaction settles, a receivable from (and a matching payable to) brokers and dealers and clearing organizations is recognized for the proceeds from the unsettled transaction.
Deposits with Clearing Organizations	Deposits with Clearing Organizations Deposits with clearing organizations are comprised of cash deposits. Due to the short-term nature of these deposits, the recorded value has been determined to approximate fair value.
Furniture, Equipment, Purchased Software and Leasehold Improvements	Furniture, Equipment, Purchased Software and Leasehold Improvements Furniture, equipment, purchased software and leasehold improvements are carried at cost less accumulated depreciation. Depreciation for furniture, equipment and purchased software, including the allocated fair value of assets as a result of pushdown accounting (see Note 3 – Pushdown Accounting), is computed on a straight-line basis over the estimated useful lives of the related assets, ranging from three to seven years. Leasehold improvements are amortized over the lesser of the estimated useful lives of the leasehold improvements or the remaining term of the lease for office space. Furniture, equipment, purchased software and leasehold improvements are tested for impairment whenever events or changes in circumstances suggest that an asset’s carrying value may not be fully recoverable in accordance with Accounting Standards Codification (“ASC”) 360, Property, Plant and Equipment .
Software Development Costs	Software Development Costs The Company capitalizes costs associated with the development of internal use software at the point at which the conceptual formulation, design and testing of possible software project alternatives have been completed, in accordance with ASC 350. The Company capitalizes employee compensation and related benefits and third party consulting costs incurred during the application development stage which directly contribute to such development. Such costs are amortized on a straight-line basis over three years. Costs capitalized as part of the pushdown accounting allocation (see Note 3 – Pushdown Accounting) are amortized over nine 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 fully recoverable, or that their useful lives are shorter than originally expected. Non-capitalized software costs and routine maintenance costs are expensed as incurred.
Goodwill	Goodwill Goodwill is the excess of the fair value of the Company above the fair value accounting basis of the net assets and liabilities of the Company under pushdown accounting. Goodwill is also the cost of acquired companies in excess of the fair value of identifiable net assets at the acquisition date. Goodwill is not amortized, but in accordance with ASC 350, goodwill is tested for impairment annually and between annual tests whenever events or changes in circumstances indicate that the carrying amount may not be fully recoverable. Goodwill is tested at the reporting unit level, which is defined as an operating segment or one level below the operating segment. An impairment loss is recognized if the estimated fair value of a reporting unit is less than its net book value. Such loss is calculated as the difference between the estimated fair value of goodwill and its carrying value. In 2019, the Company changed the annual date on which goodwill is tested for impairment from July 1 st to October 1 st to align with the annual impairment testing date of the Company’s Parent. This change did not accelerate, delay, avoid or cause an impairment charge, nor did this change result in adjustments to any previously issued financial statements. Goodwill was last assessed on October 1, 2019.
Intangible Assets	Intangible Assets Intangible assets with a finite life are amortized over the estimated lives, ranging from seven to sixteen years, in accordance with ASC 350. Intangible assets subject to amortization are tested for impairment whenever events or changes in circumstances suggest that an asset's or asset group's carrying value may not be fully recoverable in accordance with ASC 360. Intangible assets with an indefinite useful life are tested for impairment at least annually. An impairment loss is recognized if the sum of the estimated discounted cash flows relating to the asset or asset group is less than the corresponding book value.
IPO and Follow-On Offering Costs	IPO and Follow-On Offering Costs The Company began incurring costs in connection with the filing of a Registration Statement on Form S-1 for an IPO and a Registration Statement on Form S-1 for a follow-on offering in 2018 and in the third quarter of 2019, respectively. IPO and follow-on offering costs consist of legal, accounting, and other costs directly related to the Company’s efforts to raise capital. In accordance with ASC 505-10-25, Equity , these costs are recognized in additional paid-in capital within the consolidated statements of financial condition when the offering is effective. As of December 31, 2019, $15.9 million of deferred costs related to the IPO and $2.6 million of deferred costs related to the follow-on offering were recognized in additional paid-in capital in the consolidated statements of financial condition. See Note 11 – Stockholders’ Equity.
Translation of Foreign Currency	Translation of Foreign Currency Revenues and expenses denominated in foreign currencies are translated at the rate of exchange prevailing at the transaction date. Assets and liabilities denominated in foreign currencies are translated at the rate prevailing at the consolidated statements of financial condition date. Foreign currency re-measurement gains or losses on transactions in nonfunctional currencies are recognized in the consolidated statements of income. Gains or losses on translation in the financial statements of a non-U.S. operation, when the functional currency is other than the U.S. dollar, are included as a component of comprehensive income.
Income Tax	Income Tax The Corporation is subject to U.S. federal, state and local income taxes with respect to its taxable income, including its allocable share of any taxable income of TWM LLC, and is taxed at prevailing corporate tax rates. TWM LLC is a multiple member limited liability company taxed as a partnership and accordingly any taxable income generated by TWM LLC is passed through to and included in the taxable income of its members, including the Corporation, on a pro rata basis. Income taxes also include unincorporated business taxes on income earned or losses incurred for conducting business in certain state and local jurisdictions, income taxes on income earned or losses incurred in foreign jurisdictions on certain operations and federal and state income taxes on income earned or losses incurred, both current and deferred, on subsidiaries that are taxed as corporations for U.S. tax purposes. The Company records deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities. The Company measures deferred taxes using the enacted tax rates and laws that will be in effect when such temporary differences are expected to reverse. Based on the weight of the positive and negative evidence considered, management believes that it is more likely than not that the Company will be able to realize its deferred tax assets in the future, therefore, no valuation allowance is necessary. The Company records uncertain tax positions in accordance with ASC 740, Income Taxes on the basis of a two-step process whereby (i) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to income taxes within the provision for income taxes in the consolidated statements of income. Accrued interest and penalties are included within accounts payable, accrued expenses and other liabilities in the consolidated statements of financial condition. The Company has elected to treat taxes due on future U.S. inclusions in taxable income under the global intangible low-taxed income (“GILTI”) provision of the Tax Cuts and Jobs Act as a current period expense when incurred. Deferred Tax Asset Correction During the fourth quarter of 2019, the Company identified and corrected immaterial errors in the calculation of the deferred tax asset associated with the Reorganization Transactions that reduced additional paid-in-capital by $10.2 million and, reduced the deferred tax asset by $10.2 million. This correction relates to immaterial errors associated with inputs (including estimates) used in the calculation of the deferred tax balances related to the Refinitiv Contribution. This correction, if it had been recorded in the interim periods of 2019, would have reduced additional paid-in capital by $10.2 million and reduced the deferred tax asset by $10.2 million at June 30, 2019 and September 30, 2019 and would not have had a material impact on our net assets and would not have had a material impact on our consolidated results of operations or cash flows.
Revenue Recognition	Revenue Recognition The Company earns transaction fees from transactions executed on the Company’s trading platforms through various fee plans. Transaction fees are generated both on a variable and fixed price basis and vary by geographic region, product type and trade size. For variable transaction fees, the Company charges clients fees based on the mix of products traded and the volume of transactions executed. Transaction fee revenue is recorded at a point in time when the trade occurs and is generally billed monthly. The Company earns subscription fees from granting access to institutional investors to the Company's electronic marketplaces. Subscription fees are recognized into income in the period that access is provided. Also included in subscription fees are viewer fees from institutional investors accessing fixed income market data. The frequency of subscription fee billings varies from monthly to annually, depending on contract terms. Fees received by the Company which are not yet earned are included in deferred revenue on the consolidated statements of financial condition until the revenue recognition criteria has been met. The Company earns commission revenue from its electronic and voice brokerage services on a riskless principal basis. Riskless principal revenues are derived on matched principal transactions where revenues are earned on the spread between the buy and sell price of the transacted product. Securities transactions and related commission revenue for brokerage transactions are recognized and recorded on a trade-date basis. Commission revenue is collected by the Company when the trade settles or is billed monthly. The Company earns fees from Refinitiv, formerly TR in the predecessor periods, relating to the sale of market data to Refinitiv, which redistributes that data. Included in these fees, which are billed quarterly, are real-time market data fees which are recognized in the period that the data is provided, generally on a monthly basis and historical data sets which are recognized when the historical data set is provided to Refinitiv. On January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers , using the modified retrospective approach. The adoption of ASU 2014-09 did not have a material impact on the measurement or recognition of revenue in any prior reporting periods. However, subsequent to the adoption, the Company was required to make significant judgements for the Refinitiv market data fees. Significant judgements used in accounting for this contract include: · The provision of real-time market data feeds and annual historical data sets are distinct performance obligations. · The performance obligations under this contract are recognized over time from the initial delivery of the data feeds or each historical data set until the end of the contract term. · Determining the transaction price for the performance obligations by using a market assessment analysis. Inputs in this analysis include a consultant study which determined the overall value of the Company's market data and pricing information for historical data sets provided by other companies. Some revenues earned by the Company have fixed fee components, such as monthly minimums or fixed monthly fees, and variable components, such as transaction-based fees. The breakdown of revenues between fixed and variable revenues, in thousands, for the year ended December 31, 2019, the 2018 Successor Period and the 2018 Predecessor Period is as follows: Successor Successor Predecessor Year Ended October 1, 2018 to January 1, 2018 to December 31, 2019 December 31, 2018 September 30, 2018 (in thousands) Variable Fixed Variable Fixed Variable Fixed Revenues Transaction fees $ 325,178 $ 98,405 $ 73,800 $ 23,330 $ 208,049 $ 65,702 Subscription Fees including Refinitiv market data fees 1,736 192,630 425 46,094 1,305 142,676 Commissions 109,995 39,370 22,608 10,232 49,367 30,463 Other 834 7,418 — 2,148 40 8,169 Gross revenue $ 437,743 $ 337,823 $ 96,833 $ 81,804 $ 258,761 $ 247,010
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation in accordance with ASC 718, Compensation – Stock Compensation . ASC 718 focuses primarily on accounting for a transaction in which an entity obtains employee services in exchange for stock-based payments. Under ASC 718, the stock-based payments received by the employees of the Company are accounted for either as equity awards or as liability awards. As an equity award, the Company measures and recognizes the cost of employee services received in exchange for awards of equity instruments based on their estimated fair values measured as of the grant date. These costs are recognized as an expense over the requisite service period, with an offsetting increase to additional paid-in capital. As a liability award, the cost of employee services received in exchange for an award of equity instruments is generally measured based on the grant-date fair value of the award. The fair value of that award is remeasured subsequently at each reporting date through the settlement in accordance with ASC 505. Changes in the equity instrument's fair value during the requisite service period are recognized as compensation cost over that period. For periods following the Reorganization Transactions and the IPO, the fair value of new equity instrument grants is determined based on the price of the Company’s Class A common stock on the grant date. Under ASC 718, the grant-date fair value of stock-based awards that do not require future service (i.e., vested awards) are expensed immediately. The grant-date fair value of stock-based awards that require future service, and are graded-vesting awards, are amortized over the relevant service period on a straight-line basis, with each tranche separately measured. The grant-date fair value of stock-based awards that require both future service and the achievement of Company performance-based conditions, are amortized over the relevant service period for the performance-based condition. If in a reporting period it is determined that the achievement of a performance target for a performance-based tranche is not probable, then no expense is recognized for that tranche and any expenses already recognized relating to that tranche in prior reporting periods are reversed in the current reporting period. Prior to the IPO, the Company awarded options to management and other employees (collectively, the “Special Option Award”) under the Amended and Restated Tradeweb Markets Inc. Option Plan (the “Option Plan”). In accounting for the options issued under the Option Plan, or which may be issued under the Tradeweb Markets Inc. 2019 Omnibus Equity Incentive Plan (the “Omnibus Equity Plan”) in the future, compensation expense is measured and recognized for all awards based on their estimated fair values measured as of the grant date. Costs related to these options are recognized as an expense in the consolidated statements of income over the requisite service period, with an offsetting increase to additional paid-in capital. In conjunction with the IPO, the non-cash stock-based compensation expense associated with the Special Option Award began being expensed in the second quarter of 2019 and will continue to be expensed over the following three years. Determining the appropriate fair value model and calculating the fair value of the stock-based awards requires the input of highly subjective assumptions, including the expected life of the stock-based awards and the stock price volatility. The Company uses the Black-Scholes pricing model to value some of its stock-based awards. Application of alternative assumptions could produce significantly different estimates of the fair value of stock-based compensation and consequently, the related amounts recognized in the Company’s consolidated statements of income.
Fair Value Measurement	Fair Value Measurement The fair value of a financial instrument is the amount 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 (the exit price). Instruments that the Company owns (long positions) are marked to bid prices, and instruments that the Company has sold, but not yet purchased (short positions) are marked to offer prices. Fair value measurements do not include transaction costs. The fair value hierarchy under ASC 820, Fair Value Measurements prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (level 1 measurements) and the lowest priority to unobservable inputs (level 3 measurements). The three levels of the fair value hierarchy under ASC 820 are described below: Basis of Fair Value Measurement Level 1: Level 2: Level 3: A financial instrument's level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Significant Accounting Policies
Breakdown of revenues between fixed and variable revenues	The breakdown of revenues between fixed and variable revenues, in thousands, for the year ended December 31, 2019, the 2018 Successor Period and the 2018 Predecessor Period is as follows: Successor Successor Predecessor Year Ended October 1, 2018 to January 1, 2018 to December 31, 2019 December 31, 2018 September 30, 2018 (in thousands) Variable Fixed Variable Fixed Variable Fixed Revenues Transaction fees $ 325,178 $ 98,405 $ 73,800 $ 23,330 $ 208,049 $ 65,702 Subscription Fees including Refinitiv market data fees 1,736 192,630 425 46,094 1,305 142,676 Commissions 109,995 39,370 22,608 10,232 49,367 30,463 Other 834 7,418 — 2,148 40 8,169 Gross revenue $ 437,743 $ 337,823 $ 96,833 $ 81,804 $ 258,761 $ 247,010

Pushdown Accounting (Tables)

Pushdown Accounting (Tables)	12 Months Ended
	Dec. 31, 2019
Pushdown Accounting
Schedule of allocation applying pushdown accounting	The allocation applying pushdown accounting as of October 1, 2018 is summarized in the table below (in thousands): Fair Value of the Company's Net Assets $ 4,575,000 Carrying Value of the Company's Net Assets 1,880,203 Goodwill $ 2,694,797

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2019
Intangible Assets and Goodwill
Summary of intangible assets which have an indefinite useful life	The following is a summary of intangible assets which have an indefinite useful life at both December 31, 2019 and 2018 (in thousands): Amount Licenses $ 168,800 Tradename 154,300 Total $ 323,100
Intangible assets that are subject to amortization	Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised as follows (in thousands): Successor Successor December 31, 2019 December 31, 2018 Amortization Accumulated Net Carrying Accumulated Net Carrying Period Cost Amortization Amount Cost Amortization Amount Customer relationships 12 Years $ 928,200 $ (96,687) $ 831,513 $ 928,200 $ (19,338) $ 908,862 Content and data 7 Years 154,400 (27,572) 126,828 154,400 (5,514) 148,886 $ 1,082,600 $ (124,259) $ 958,341 $ 1,082,600 $ (24,852) $ 1,057,748

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases
Activity related to the company's leases	Activity related to the Company's leases for the year ended December 31, 2019 is as follows (in thousands): Year Ended December 31, 2019 Operating lease expense $ 10,265 Cash for amounts included in the measurement of operating liability $ 11,667 Right-of-use assets obtained in exchange for operating liabilities $ — At December 31, 2019, the weighted average borrowing rate and weighted average lease term are as follows: Amount Weighted average borrowing rate 2.9 % Weighted average remaining lease term (years) 5.9
Schedule of maturity of lease liabilities and future minimum lease payments	The following table presents the maturity of lease liabilities as of December 31, 2019 (in thousands): Amount 2020 $ 8,516 2021 5,946 2022 4,143 2023 3,956 2024 3,558 Thereafter 7,633 Total future lease payments 33,752 Less imputed interest (2,797) Lease liability $ 30,955 At December 31, 2019, the future minimum lease payments were as follows (in thousands): Amount 2020 $ 8,516 2021 5,946 2022 4,143 2023 3,956 2024 3,558 Thereafter 7,633 Total $ 33,752
Schedule of future minimum lease payments	At December 31, 2018, the future minimum lease payments were as follows (in thousands): Amount 2019 $ 11,393 2020 7,580 2021 5,317 2022 4,051 2023 3,877 Thereafter 11,156 Total $ 43,374

Deferred Revenue (Tables)

Deferred Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Deferred Revenue
Schedule of recognized revenue and remaining deferred revenue balance	The recognized revenue and remaining balance is shown below (in thousands): Amount Deferred revenue balance - December 31, 2018 $ 27,883 New billings 106,153 Revenue recognized (110,046) Deferred revenue balance - December 31, 2019 $ 23,990

Software Development Cost (Tabl

Software Development Cost (Tables)	12 Months Ended
	Dec. 31, 2019
Software Development Cost
Components of software development costs	The components of Software development costs, net of accumulated amortization are as follows (in thousands): Successor Successor Year Ended Year Ended December 31, December 31, 2019 2018 Software development costs $ 204,336 $ 175,656 Accumulated amortization (31,250) (5,074) Software development costs, net of accumulated amortization $ 173,086 $ 170,582
Schedule of non-capitalized software costs and routine maintenance costs	Successor Successor Predecessor Predecessor Year Ended October 1, 2018 January 1, 2018 Year Ended December 31, to to December 31, 2019 December 31, 2018 September 30, 2018 2017 Software development costs capitalized $ 26,681 $ 7,156 $ 19,523 $ 27,157 Amortization expense related to capitalized software development costs $ 26,176 $ 5,074 $ 19,962 $ 25,420

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Taxes
Components of provision for income taxes	The provision for income taxes consists of the following (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Current: Federal $ 21,373 $ — $ — $ — State and Local 11,537 1,235 5,739 4,331 Foreign 4,368 1,212 3,559 2,748 Total current tax expense 37,278 2,447 9,298 7,079 Deferred: Federal (88) 680 1,085 (433) State and local 18,194 288 1,517 (517) Foreign (3,082) — — — Total deferred tax expense 15,024 968 2,602 (950) Total provision for income taxes $ 52,302 $ 3,415 $ 11,900 $ 6,129
Reconciliation of the statutory tax rate	Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Current: Federal $ 21,373 $ — $ — $ — State and Local 11,537 1,235 5,739 4,331 Foreign 4,368 1,212 3,559 2,748 Total current tax expense 37,278 2,447 9,298 7,079 Deferred: Federal (88) 680 1,085 (433) State and local 18,194 288 1,517 (517) Foreign (3,082) — — — Total deferred tax expense 15,024 968 2,602 (950) Total provision for income taxes $ 52,302 $ 3,415 $ 11,900 $ 6,129 A reconciliation of the statutory tax rate to the effective rate is as follows: Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Statutory U.S. federal income tax rate 21.0 % 21.0 % 21.0 % 35.0 % State and local income taxes, net of federal income tax benefit 3.9 4.7 5.1 2.8 Foreign tax rate differential (1.1) 3.7 2.5 3.1 Tax Cuts and Jobs Act Provisional Tax Charge — — — 2.2 LLC flow-through structure — (19.0) (20.2) (36.3) Non-Controlling Interest (7.2) — — — Tax Receivable Agreement adjustment (3.1) — — — Rate Change 10.2 — — — Other (0.5) — — — Effective income tax rate $ 23.2 % $ 10.4 % $ 8.4 % $ 6.8 %
Components of deferred tax assets (Liabilities)	The components of the Company’s net deferred tax asset (liability) are as follows (in thousands): Successor Successor Year Ended Year Ended December 31, December 31, 2019 2018 Deferred tax assets: Investment in partnership $ 226,241 $ — Net operating losses 1,753 6,810 Tax Receivable Agreement - Interest 10,395 — Employee compensation 9,888 — Credits 8,342 — Other 4,088 2,362 Deferred tax assets, gross 260,707 9,172 Valuation Allowance — — Total deferred tax assets, net 260,707 9,172 Deferred tax liabilities Goodwill and Intangibles (25,829) (28,799) Total deferred tax liabilities (25,829) (28,799) Total net deferred tax asset (liability) $ 234,878 $ (19,627)
Components of uncertain tax positions	The components of the Company’s uncertain tax positions are as follows (dollars in thousands): Successor December 31, 2019 Gross unrecognized tax benefits as of January 1 $ 3,348 Increase in current year tax positions 2,162 Increase in prior year tax positions - Acquired tax positions 1,789 Settlements (787) Gross unrecognized tax benefits as of December 31 $ 6,512

Stockholders_ Equity (Tables)

Stockholders’ Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Stockholder's Equity
Schedule of class of common stock par value, votes and economic rights	Class of Par Votes Economic Class A common stock $ 1 Yes Class B common stock $ 10 Yes Class C common stock $ 1 No Class D common stock $ 10 No
Schedule of common units outstanding	Shares Class A 146,333 Class C 447 Class P (A) 6,887 Class P (C) 2 Class P-1(A) 6,094 Class P-1 (C) 232

Non-Controlling Interests (Tabl

Non-Controlling Interests (Tables)	12 Months Ended
	Dec. 31, 2019
Non-Controlling Interests
Summary of the ownership interest in noncontrolling interest	December 31, 2019 LLC Ownership Interests % Number of LLC Interests held by Tradeweb Markets Inc. 163,341,520 Number of LLC Interests held by non-controlling interests 59,182,155 Total LLC Interests outstanding 222,523,675
Summary of the impact on equity due to changes in the Company’s ownership interest in noncontrolling interest	The following table summarizes the impact on equity due to changes in the Corporation’s ownership interest in TWM LLC (in thousands): Successor Year Ended December 31, Net Income Attributable to Tradeweb Markets Inc. and Transfers (to) from the Non-Controlling Interests 2019 Net income attributable to Tradeweb Markets Inc. $ 83,769 Transfers (to) from non-controlling interests: Allocation of equity to non-controlling interests arising from the reorganization transactions and IPO (1,607,529) Change in non-controlling interests as a result of the October 2019 follow-on offering and other ownership changes 402,227 Net transfers (to) from non-controlling interests (1,205,302) Change from net income attributable to Tradeweb Markets Inc. and transfers (to) from non-controlling interests $ (1,121,533)

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of options issued	A summary of the Company’s outstanding options is presented below: Weighted Average Grant-Date Options Fair Value Options outstanding at December 31, 2018 18,091,793 $ 1.85 Grants 886,115 $ 8.83 Exercises (984,585) $ 1.80 Forfeitures and adjustments (253,579) $ 2.67 Options outstanding at December 31, 2019 17,739,744 $ 2.19 Vested options outstanding at December 31, 2019 $
Schedule of assumptions used to estimate the fair value of the options	The significant assumptions used to estimate the fair value of the options as of the grant date were as follows: Weighted Average Expected Life (years) 5.7 Weighted Average Risk-Free Interest Rate 2.9 % Weighted Average Expected Volatility 20.0 % Weighted Average Expected Dividend Yield 3.9 % Weighted Average Share Price $ 21.62 Weighted Average Exercise Price $ 21.62
Schedule of unrecognized compensation expense	As of December 31, 2019, total unrecognized compensation expense related to unvested stock-based compensation arrangements and the expected recognition period are as follows (dollars in thousands): Cash-Settled Equity-Settled PRSUs PRSUs Options Total unrecognized compensation cost $ 383 $ 31,283 $ 4,068 Weighted-average recognition period 1.0 years 1.7 years 2.8 years
Equity-settled PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of equity-settled PRSUs issued	A summary of the Company’s outstanding equity-settled PRSUs is presented below: Weighted Average Equity-Settled Grant-Date PRSUs Fair Value Equity-settled PRSUs outstanding at December 31, 2018 2,000,384 $ 9.53 Grants 781,026 $ 21.08 Vests — $ — Performance adjustment 762,326 $ 21.08 Forfeitures (53,070) $ 13.48 Equity-settled PRSUs outstanding at December 31, 2019 3,490,666 $ 14.59
Schedule of unrecognized compensation expense	The following table shows a summary of equity-settled PRSU activity during the year ended December 31, 2019 (in thousands): Successor Year Ended December 31, 2019 Equity-settled PRSU compensation expense $ 25,392 Income tax benefit $ (4,781)
Cash-settled PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of equity-settled PRSUs issued	A summary of the Company’s outstanding cash-settled PRSUs is presented below: Weighted Cash-Settled Average PRSUs Fair Value Cash-settled PRSUs outstanding at December 31, 2018 522 $ 34,221 Grants — $ — Vests (1) (507) $ 33,842 Forfeitures — $ — Cash-settled PRSUs outstanding at December 31, 2019 15 $ 94,997 (1) The total fair value of cash-settled PRSUs vested was $17.2 million for the year ended December 31, 2019.
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of unrecognized compensation expense	The following table shows a summary options activity during the year ended December 31, 2019 (in thousands): Successor Year Ended December 31, 2019 Options compensation expense $ 24,432 Income tax benefit $ (8,556)

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Related Party Transactions
Schedule of balances from transactions with affiliates included in the consolidated statements	At December 31, 2019 and 2018, the following balances with such affiliates were included in the consolidated statements of financial condition in the following line items (in thousands): Successor Successor December 31, 2019 December 31, 2018 Cash and cash equivalents $ — $ 283,790 Receivables from brokers and dealers and clearing organizations — 3,332 Deposits with clearing organizations — 500 Accounts receivable — 40,730 Receivable from affiliates 2,525 3,243 Other assets — 9 Payable to brokers and dealers and clearing organizations — 2,404 Deferred revenue 4,733 9,151 Payable to affiliates 1,506 5,009
Schedule of affiliates were included in the consolidated statements of income	The following balances with such affiliates were included in the consolidated statements of income in the following line items (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 January 1, 2018 Year Ended December 31, to to December 31, 2019 December 31, 2018 September 30, 2018 2017 Revenue: Transaction fees (1) $ 59,643 $ 59,259 $ 159,663 $ 151,695 Subscription fees (1) 5,670 5,718 16,627 37,426 Commissions (1) 16,186 12,401 34,944 43,315 Refinitiv market data fees (2) 55,635 13,467 36,851 50,125 Operating Income: (3) Net interest income (expense) 858 17 (415) Shared Services Fees (4) : Technology and communications 2,960 740 2,220 2,960 General and administrative 430 180 539 719 Occupancy 481 155 466 621 (1) For pre-IPO periods, represents fees and commissions from affiliates of the Bank Stockholders. (2) The Company maintains a market data license agreement with Refinitiv (TR in the predecessor period). Under the agreement, the Company delivers to Refinitiv certain market data feeds which Refinitiv redistributes to its customers. The Company earns license fees and royalties for these feeds. (3) For pre-IPO periods, represents interest income from money market funds invested with and savings accounts deposited with affiliates of the Bank Stockholders. (4) The Company maintains a shared services agreement with Refinitiv (TR in the predecessor period). Under the terms of the agreement, Refinitiv provides the Company with certain real estate, payroll, benefits administration, insurance, content, financial reporting and tax support.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value of Financial Instruments
Schedule of fair value measurements	The fair value measurements are as follows (in thousands): Quoted Prices in active Markets Significant Significant for Identical Observable Unobservable Assets Inputs Inputs Successor (Level 1) (Level 2) (Level 3) Total As of December 31, 2019 Assets Money market funds $ 219,158 $ — $ — $ 219,158 $ 219,158 $ — $ — $ 219,158 As of December 31, 2018 Assets Money market funds $ 127,927 $ — $ — $ 127,927 $ 127,927 $ — $ — $ 127,927

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Tradeweb Markets LLC
Entity Information [Line Items]
Schedule of basic and Diluted earnings per share	Successor Successor Predecessor Predecessor Three Months Ended October 1, 2018 to January 1, 2018 to Year Ended March 31, December 31, September 30, December 31, EPS: Pre-IPO net income attributable to Tradeweb Markets LLC (1) 2019 2018 2018 2017 (in thousands, except share and per share amounts) Numerator: Pre-IPO net income attributable to Tradeweb Markets LLC $ 42,352 $ 29,307 $ 130,160 $ 83,648 Denominator: Weighted average LLC Interests outstanding - Basic 222,222,197 222,221,628 215,365,920 212,568,635 Dilutive effect of equity-settled PRSUs 1,098,260 22,223 — — Weighted average LLC Interests outstanding - Diluted 223,320,457 222,243,851 215,365,920 212,568,635 Earnings per share - Basic $ 0.19 $ 0.13 $ 0.60 $ 0.39 Earnings per share - Diluted $ 0.19 $ 0.13 $ 0.60 $ 0.39 (1) Earnings per share and weighted average shares outstanding for the pre-IPO periods have been computed to give effect to the Reorganization Transactions, including the amendment and restatement of the TWM LLC Agreement to, among other things, (i) provide for LLC Interests and (ii) exchange all of the then existing membership interests in TWM LLC for LLC interests. The following table summarizes the basic and diluted earnings per share calculations for Tradeweb Markets Inc. (post-IPO period): Successor Nine Months Ended EPS: Post-IPO net income attributable to Tradeweb Markets Inc. December 31, (in thousands, except share and per share amounts) 2019 Numerator: Post-IPO net income attributable to Tradeweb Markets Inc. $ 83,769 Denominator: Weighted average shares of Class A and Class B common stock outstanding - Basic 148,013,274 Dilutive effect of equity-settled PRSUs 2,464,137 Dilutive effect of options 6,062,835 Weighted average shares of Class A and Class B common stock outstanding - Diluted 156,540,246 Earnings per share - Basic $ 0.57 Earnings per share - Diluted $ 0.54

Regulatory Capital Requiremen_2

Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2019
Regulatory Capital Requirements
Schedule of regulatory capital requirements	At December 31, 2019 and 2018, the regulatory capital requirements and regulatory capital for TWL, DW, TWD, TEL, TWJ and TWEU are as follows (in thousands): As of December 31, 2019 TWL DW TWD TEL TWJ TWEU Regulatory Capital $ 42,317 $ 52,016 $ 33,807 $ 49,611 $ 11,851 $ 6,217 Regulatory Capital Requirement 2,396 2,026 664 21,856 8,565 1,701 Excess Regulatory Capital $ 39,921 $ 49,990 $ 33,143 $ 27,755 $ 3,286 $ 4,516 As of December 31, 2018 TWL DW TWD TEL TWJ Regulatory Capital $ 18,986 $ 41,164 $ 24,042 $ 46,157 $ 10,592 Regulatory Capital Requirement 2,698 1,803 599 17,493 3,413 Excess Regulatory Capital $ 16,288 $ 39,361 $ 23,443 $ 28,664 $ 7,179
Schedule of financial resources and liquid financial resources	The required and maintained financial resources and liquid financial assets at December 31, 2019 and 2018 are as follows (in thousands): As of December 31, 2019 As of December 31, 2018 TW SEF DW SEF TW SEF DW SEF Financial Resources $ 21,303 $ 13,707 $ 31,232 $ 17,837 Required Financial Resources 10,500 5,505 10,500 5,169 Excess Financial Resources $ 10,803 $ 8,202 $ 20,732 $ 12,668 Liquid Financial Assets $ 18,168 $ 7,583 $ 16,662 $ 11,888 Required Liquid Financial Assets 5,250 2,753 5,250 2,585 Excess Liquid Financial Assets $ 12,918 $ 4,830 $ 11,412 $ 9,303

Business Segment and Geograph_2

Business Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2019
Business Segment and Geographic Information
Schedule of information regarding revenue by client sector	The Company operates electronic marketplaces for the trading of products across the rates, credit, equities and money markets asset classes and provides related pre-trade and post-trade services. The Company’s operations constitute a single business segment because of the integrated nature of these marketplaces and services. Information regarding revenue by client sector is as follows (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Net revenue: Institutional $ 453,379 $ 103,971 $ 301,918 $ 318,038 Wholesale 171,096 38,153 99,028 118,451 Retail 80,368 19,780 57,766 70,857 Market Data 70,723 16,733 47,059 55,622 Contingent consideration — — (26,830) (58,520) Net revenue 775,566 178,637 478,941 504,448 Operating expenses 585,747 146,702 338,607 415,356 Operating income $ 189,819 $ 31,935 $ 140,334 $ 89,092
Schedule of revenue and long-lived assets by geographic location	The following table provides a breakdown of revenue by geographic area for the year ended December 31, 2019, the 2018 Successor Period, the 2018 Predecessor Period and the year ended December 31, 2017 (in thousands): Successor Successor Predecessor Predecessor Year Ended October 1, 2018 to January 1, 2018 to Year Ended December 31, December 31, September 30, December 31, 2019 2018 2018 2017 Net Revenue: U.S. $ 497,316 $ 115,907 $ 324,304 $ 385,176 International 278,250 62,730 181,467 177,792 Gross revenue 775,566 178,637 505,771 562,968 Contingent consideration — — (26,830) (58,520) Total $ 775,566 $ 178,637 $ 478,941 $ 504,448 The following table provides information on the attribution of long-lived assets by geographic area (in thousands): Successor Successor December 31, December 31, 2019 2018 Long-lived assets U.S. $ 4,200,133 $ 4,276,568 International 14,100 7,787 Total $ 4,214,233 $ 4,284,355

Quarterly Results of Operatio_2

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Results of Operations (Unaudited)
Schedule of quarterly operating results	The operating results for any quarter are not necessarily indicative of results for any future period. Tradeweb Markets Inc. (post-IPO) Tradeweb Markets LLC (pre-IPO) Successor Successor Successor Successor Successor Predecessor Predecessor Predecessor Three Months Ended December 31, September 30, June 30, March 31, December 31, September 30, June 30, March 31, 2019 2019 2019 2019 2018 2018 2018 2018 Revenues (in thousands, except share and per share data) Transaction fees $ 104,245 $ 112,746 $ 103,952 $ 102,640 $ 97,130 $ 92,582 $ 91,030 $ 90,139 Subscription fees 34,333 35,387 34,566 34,445 33,052 33,157 37,647 36,326 Commissions 41,165 37,590 36,413 34,197 32,840 24,394 27,553 27,883 Refinitiv market data fees 15,383 13,251 13,385 13,616 13,467 12,533 12,081 12,237 Other 2,182 2,007 2,169 1,894 2,148 2,587 2,704 2,918 Gross revenue 197,308 200,981 190,485 186,792 178,637 165,253 171,015 169,503 Contingent consideration — — — — — 2,537 (19,297) (10,070) Net revenue 197,308 200,981 190,485 186,792 178,637 167,790 151,718 159,433 Expenses Employee compensation and benefits 76,545 79,644 95,995 77,273 80,436 69,076 68,407 71,570 Depreciation and amortization 36,402 35,133 34,292 33,503 33,020 16,362 16,178 16,268 Technology and communications 10,199 9,527 9,519 10,040 9,907 9,112 9,023 8,463 General and administrative 8,999 7,507 9,365 9,089 11,837 9,386 7,153 6,517 Professional fees 7,048 7,272 6,738 6,971 8,194 7,546 7,276 5,538 Occupancy 3,786 3,640 3,621 3,639 3,308 3,491 3,519 3,722 Total expenses 142,979 142,723 159,530 140,515 146,702 114,973 111,556 112,078 Operating income 54,329 58,258 30,955 46,277 31,935 52,817 40,162 47,355 Tax receivable agreement liability adjustment 33,134 — — — — — — — Net interest income 704 636 175 858 787 673 582 471 Income before taxes 88,167 58,894 31,130 47,135 32,722 53,490 40,744 47,826 Provision for income taxes (30,889) (10,316) (6,314) (4,783) (3,415) (7,535) (1,847) (2,518) Net income $ 57,278 $ 48,578 $ 24,816 $ 42,352 $ 29,307 $ 45,955 $ 38,897 $ 45,308 Net income attributable to non-controlling interests $ 15,949 $ 18,966 $ 11,988 Net income attributable to Tradeweb Markets Inc. $ 41,329 $ 29,612 $ 12,828 Earnings per share (1) Basic $ $ $ $ $ $ $ $ Diluted $ $ $ $ $ $ $ $ Weighted average shares outstanding Basic 157,950,550 142,935,206 142,933,192 222,222,197 222,221,628 219,165,997 213,435,314 213,435,321 Diluted 167,323,520 151,362,643 150,847,183 223,320,457 222,243,851 219,165,997 213,435,314 213,435,321

Organization (Details)

Organization (Details) - USD ($) $ / shares in Units, $ in Billions	Apr. 08, 2019	Oct. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Jun. 28, 2019
Weighted Weighted Average Share Price				$ 21.62
Shares contributed by Refinitiv Owner			96,933,192
Class A common stock
Common Stock, par value per share				$ 0.00001
Shares issued				46,000,000
Class B common stock
Common Stock, par value per share				$ 0.00001	$ 0.00001
Shares issued	96,933,192			96,933,192
Number of shares canceled	9,993,731
Shares contributed by Refinitiv Owner	96,933,192
Class C common stock
Common Stock, par value per share				$ 0.00001
Shares issued				10,006,269
Shares issued to acquire TWM LLC	20,000,000
Number of shares canceled	9,993,731
Class D common stock
Common Stock, par value per share				$ 0.00001
Shares issued				69,282,736
Shares issued to acquire TWM LLC	105,289,005
Number of shares canceled	36,006,269
Tradeweb Markets LLC
Ownership interest	64.30%			73.40%
Equity interest of noncontrolling shareholders in consolidated entity				26.60%
Weighted Weighted Average Share Price	$ 27
Net proceeds	$ 1.2
Initial Public Offering | Class A common stock
Common Stock, par value per share	$ 0.00001
Shares issued	46,000,000
Weighted Weighted Average Share Price	$ 27
Over allotment | Class A common stock
Shares issued	6,000,000	2,593,181

Significant Accounting Polici_4

Significant Accounting Policies - Useful Lives of Assets (Details)	12 Months Ended
	Dec. 31, 2019
Furniture, Equipment, Purchased Software and Leasehold Improvements | Minimum
Furniture, Equipment, Purchased Software and Leasehold Improvements
Property, Plant and Equipment, Useful Life	3 years
Furniture, Equipment, Purchased Software and Leasehold Improvements | Maximum
Furniture, Equipment, Purchased Software and Leasehold Improvements
Property, Plant and Equipment, Useful Life	7 years
Software Development Costs
Furniture, Equipment, Purchased Software and Leasehold Improvements
Property, Plant and Equipment, Useful Life	3 years
Amortization of pushdown accounting allocation	9 years

Significant Accounting Polici_5

Significant Accounting Policies - Useful Lives of Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2019
Minimum
Intangible Assets
Useful life of intangible assets	7 years
Maximum
Intangible Assets
Useful life of intangible assets	16 years

Significant Accounting Polici_6

Significant Accounting Policies - Deferred IPO Cost and Deferred Tax Assets Correction (Details) $ in Millions	Dec. 31, 2019USD ($)
Initial Public Offering
Deferred costs	$ 15.9
Follow On Offering
Deferred costs	$ 2.6

Significant Accounting Polici_7

Significant Accounting Policies - Breakdown of Revenues Between Fixed and Variable (Details) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue Recognition
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor				Successor	Predecessor	Successor	Successor	Predecessor
Gross revenues		$ 178,637					$ 505,771	$ 775,566		$ 562,968
Compensation expense		9,400					15,900	50,700		26,100
Transaction fees
Revenue Recognition
Gross revenues		97,130					273,751	423,583		267,020
Commissions
Revenue Recognition
Gross revenues		32,840					79,830	149,365		96,745
Other
Revenue Recognition
Gross revenues		$ 2,148					$ 8,209	$ 8,252		$ 4,669
Variable
Revenue Recognition
Financial Designation, Predecessor and Successor [Fixed List]		Successor					Predecessor	Successor
Gross revenues		$ 96,833					$ 258,761	$ 437,743
Variable | Transaction fees
Revenue Recognition
Gross revenues		73,800					208,049	325,178
Variable | Subscription Fees including Refinitiv market data
Revenue Recognition
Gross revenues		425					1,305	1,736
Variable | Commissions
Revenue Recognition
Gross revenues		$ 22,608					49,367	109,995
Variable | Other
Revenue Recognition
Gross revenues							$ 40	$ 834
Fixed
Revenue Recognition
Financial Designation, Predecessor and Successor [Fixed List]		Successor					Predecessor	Successor
Gross revenues		$ 81,804					$ 247,010	$ 337,823
Fixed | Transaction fees
Revenue Recognition
Gross revenues		23,330					65,702	98,405
Fixed | Subscription Fees including Refinitiv market data
Revenue Recognition
Gross revenues		46,094					142,676	192,630
Fixed | Commissions
Revenue Recognition
Gross revenues		10,232					30,463	39,370
Fixed | Other
Revenue Recognition
Gross revenues		$ 2,148					$ 8,169	$ 7,418
Tradeweb Markets LLC
Revenue Recognition
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Predecessor	Predecessor	Predecessor
Gross revenues	$ 186,792	$ 178,637	$ 165,253	$ 171,015	$ 169,503
Tradeweb Markets LLC | Transaction fees
Revenue Recognition
Gross revenues	102,640	97,130	92,582	91,030	90,139
Tradeweb Markets LLC | Commissions
Revenue Recognition
Gross revenues	34,197	32,840	24,394	27,553	27,883
Tradeweb Markets LLC | Other
Revenue Recognition
Gross revenues	$ 1,894	$ 2,148	$ 2,587	$ 2,704	$ 2,918

Significant Accounting Polici_8

Significant Accounting Policies - Stock-Based Compensation (Details)	3 Months Ended
	Jun. 30, 2019
Special Mention
Stock-Based Compensation
Allocation term	3 years

Significant Accounting Polici_9

Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use assets		$ 24,504
Lease liability		$ 30,955
ASC 842
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 34,800
Lease liability	39,600
Deferred rent	$ 4,900
Package of practical expedients	true	true

Pushdown Accounting (Details)

Pushdown Accounting (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Oct. 01, 2018
Entity Information [Line Items]
Fair Value of the Company's Net Assets			$ 4,575,000
Carrying Value of the Company's Net Assets			1,880,203
Goodwill	$ 2,694,797	$ 2,694,797	2,694,797
Software development costs
Entity Information [Line Items]
Fair Value of the Company's Net Assets			$ 168,500

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Indefinite Lived Intangible Assets (Details) $ in Thousands	Dec. 31, 2019USD ($)
Intangible assets with indefinite useful lives
Intangible assets which have an indefinite useful life	$ 323,100
Licenses
Intangible assets with indefinite useful lives
Intangible assets which have an indefinite useful life	168,800
Tradenames
Intangible assets with indefinite useful lives
Intangible assets which have an indefinite useful life	$ 154,300

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill - Finite Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Intangible assets that are subject to amortization
Cost	$ 1,082,600	$ 1,082,600
Accumulated Amortization	(124,259)	(24,852)
Net Carrying Amount	$ 958,341	$ 1,057,748
Customer relationships
Intangible assets that are subject to amortization
Amortization Period	12 years	12 years
Cost	$ 928,200	$ 928,200
Accumulated Amortization	(96,687)	(19,338)
Net Carrying Amount	$ 831,513	$ 908,862
Content and data
Intangible assets that are subject to amortization
Amortization Period	7 years	7 years
Cost	$ 154,400	$ 154,400
Accumulated Amortization	(27,572)	(5,514)
Net Carrying Amount	$ 126,828	$ 148,886

Intangible Assets and Goodwil_4

Intangible Assets and Goodwill - Future Amortization (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019
Intangible Assets and Goodwill
Amortization expense	$ 24.9	$ 19.6	$ 99.4

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use assets		$ 24,504
Lease liability		30,955
Activity related to the Company's leases
Operating lease expense		10,265
Cash for amounts included in the measurement of operating liability		$ 11,667
Weighted average borrowing rate		2.90%
Weighted average remaining lease term (years)		5 years 10 months 24 days
Minimum
Lessee, Lease, Description [Line Items]
Initial term of lease		3 years
Maximum
Lessee, Lease, Description [Line Items]
Initial term of lease		11 years
ASC 842
Lessee, Lease, Description [Line Items]
Package of practical expedients	true	true
Right-of-use assets	$ 34,800
Lease liability	39,600
Deferred rent	4,900
ASC 842 | Adjustment
Lessee, Lease, Description [Line Items]
Right-of-use assets	31,800
Lease liability	39,600
Deferred rent	$ 4,900

Leases - Maturity of Lease Liab

Leases - Maturity of Lease Liabilities and Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2019USD ($)
Maturity of lease liabilities
2020	$ 8,516
2021	5,946
2022	4,143
2023	3,956
2024	3,558
Thereafter	7,633
Total future minimum lease payments	33,752
Less imputed interest	(2,797)
Lease liability	$ 30,955

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments - 2018 (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2019
Future minimum rental payments
2019				$ 11,393
2020				7,580
2021				5,317
2022				4,051
2023				3,877
Thereafter				11,156
Total				$ 43,374
Rent expense	$ 2,700	$ 9,000	$ 11,800

Leases - Guaranteed (Details)

Leases - Guaranteed (Details) $ in Millions	Dec. 31, 2019USD ($)
Refinitiv | US lease secured by letter of credit
Guarantor Obligations [Line Items]
Letter of credit guaranteed by Refinitiv	$ 1.2

Restricted Cash (Details)

Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Restricted Cash
Restricted cash	$ 1,000	$ 1,200

Deferred Revenue (Details)

Deferred Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Changes in deferred revenue
Deferred revenue balance - beginning of period	$ 27,883
New billings	106,153
Revenue recognized	(110,046)
Deferred revenue balance - end of period	$ 23,990

Software Development Cost (Deta

Software Development Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Software Development Cost
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Software development costs		$ 175,656	$ 204,336		$ 204,336	$ 175,656
Accumulated amortization		(5,074)	(31,250)		(31,250)	(5,074)
Software development costs, net of accumulated amortization		170,582	$ 173,086		173,086	$ 170,582
Software development costs capitalized		7,156		$ 19,523	26,681		$ 27,157
Amortization expense related to non-capitalized software costs and routine maintenance costs		$ 5,074		$ 19,962	$ 26,176		$ 25,420

Income Taxes - Income (loss) be

Income Taxes - Income (loss) before provision for tax (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Total income before provision for income taxes		$ 32,722		$ 142,060	$ 225,326		$ 89,777
United States
Income Tax Disclosure [Line Items]
Total income before provision for income taxes					207,700
Foreign
Income Tax Disclosure [Line Items]
Total income before provision for income taxes					$ 17,600

Income Taxes - Components of Pr

Income Taxes - Components of Provision (Tradeweb Markets LLC and Subsidiaries) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Federal					$ 21,373
State and Local		$ 1,235		$ 5,739	11,537		$ 4,331
Foreign		1,212		3,559	4,368		2,748
Total current tax expense		2,447		9,298	37,278		7,079
Deferred:
Federal		680		1,085	(88)		(433)
State and local		288		1,517	18,194		(517)
Foreign					(3,082)
Total deferred tax expense		968		2,602	15,024		(950)
Total provision for income taxes		$ 3,415		$ 11,900	$ 52,302		$ 6,129

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Statutory Rate (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of the statutory tax rate
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Statutory U.S. federal income tax rate		21.00%		21.00%	21.00%		35.00%
State and local income taxes, net of federal income tax benefit		4.70%		5.10%	3.90%		2.80%
Foreign tax rate differential		3.70%		2.50%	(1.10%)		3.10%
Tax Cuts & Jobs Act Provisional Tax Charge							0.022
LLC flow-through structure		(19.00%)		(20.20%)			(36.30%)
Non-Controlling Interest					(7.20%)
Tax Receivable Agreement adjustment					(3.10%)
Rate Change					10.20%
Other					(0.50%)
Effective tax rate		10.40%		8.40%	23.20%		6.80%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Asset (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Investment in partnerships			$ 226,241		$ 226,241
Net operating losses		$ 6,810	1,753		1,753	$ 6,810
Tax Receivable Agreement			10,395		10,395
Employee compensation			9,888		9,888
Credits			8,342		8,342
Other		2,362	4,088		4,088	2,362
Deferred tax assets, gross		9,172	260,707		260,707	9,172
Total deferred tax assets, net		9,172	260,707		260,707	9,172
Deferred tax liabilities
Goodwill and Intangibles		(28,799)	(25,829)		(25,829)	(28,799)
Total deferred tax liabilities		(28,799)	(25,829)		(25,829)	(28,799)
Total deferred tax asset (liability)			$ 234,878		$ 234,878
Total deferred tax asset (liability)		$ (19,627)				$ (19,627)

Income Taxes - Uncertain Tax Po

Income Taxes - Uncertain Tax Position (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Gross unrecognized tax benefits as of January 1	$ 3,348				$ 3,348
Increase in current year tax positions					2,162
Acquired tax positions					1,789
Settlements					(787)
Gross unrecognized tax benefits as of December 31		$ 3,348	$ 6,512		6,512	$ 3,348
Decrease in unrecognized tax benefits					$ 1,300

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2017
Income Taxes
Effective Income Tax Rate Reconciliation, Percent	10.40%		8.40%	23.20%	6.80%
Reduction in deferred tax asset				10.20%
Additional paid-in-capital adjustment		$ (4,382)
Settlements				$ 787
Tax Amortization Period				15 years
Accounts payable, accrued expenses and other liabilities
Income Taxes
Tax, penalties and interest expense				$ 2,300
Tax, penalties and interest provision		500		500
Accrued Income Taxes		2,700		2,700
New York state
Income Taxes
Net operating loss carryforwards		15,700		15,700
New York City
Income Taxes
Net operating loss carryforwards		$ 13,900		$ 13,900

Tax Receivable Agreement (Detai

Tax Receivable Agreement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Apr. 08, 2019
Tax Receivable Agreement
Percentage of amount of U.S. federal, state and local income or franchise tax savings	50.00%
Tax receivable agreement liability	$ 240,817	$ 171,400

Stockholder's Equity (Details)

Stockholder's Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 08, 2019	Oct. 31, 2019	Dec. 31, 2019	Dec. 31, 2019
Subsidiary, Sale of Stock [Line Items]
Weighted Weighted Average Share Price			$ 21.62	$ 21.62
LLC units | October 2019 Follow-On Offering
Subsidiary, Sale of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares		19,835,666
Class A common stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)				46,000,000
Class A common stock | October 2019 Follow-On Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)			19,881,059
Weighted Weighted Average Share Price		$ 42
Net proceeds		$ 810
Stock Repurchased and Retired During Period, Shares		45,393
Class A common stock | Initial Public Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)	46,000,000
Weighted Weighted Average Share Price	$ 27
Class A common stock | Over allotment
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)	6,000,000	2,593,181
Tradeweb Markets LLC
Subsidiary, Sale of Stock [Line Items]
Weighted Weighted Average Share Price	$ 27
Net proceeds	$ 1,200

Stockholder's Equity - Authoriz

Stockholder's Equity - Authorized shares (Details)	12 Months Ended
	Dec. 31, 2019Vote$ / sharesshares	Jun. 28, 2019$ / shares	Apr. 08, 2019	Dec. 31, 2018$ / sharesshares
Class of Stock [Line Items]
Preferred stock, shares authorized | shares	250,000,000			250,000,000
Preferred stock, par value | $ / shares	$ 0.00001			$ 0.00001
Class A common stock
Class of Stock [Line Items]
Common Stock, shares authorized | shares	1,000,000,000
Common stock, par value | $ / shares	$ 0.00001
Number of votes per common stock | Vote	1
Conversion ratio	1
Class B common stock
Class of Stock [Line Items]
Common Stock, shares authorized | shares	450,000,000
Common stock, par value | $ / shares	$ 0.00001	$ 0.00001
Number of votes per common stock | Vote	10
Class C common stock
Class of Stock [Line Items]
Common Stock, shares authorized | shares	350,000,000
Common stock, par value | $ / shares	$ 0.00001
Number of votes per common stock | Vote	1
Conversion ratio	1
Class D common stock
Class of Stock [Line Items]
Common Stock, shares authorized | shares	300,000,000
Common stock, par value | $ / shares	$ 0.00001
Number of votes per common stock | Vote	10
Voting power threshold percentage to require conversion of shares			4.90%
Tradeweb Markets LLC
Class of Stock [Line Items]
Threshold percentage of economic interest for conversion	10.00%
Cancellation ratio	1
Minimum | Class D common stock
Class of Stock [Line Items]
Voting power threshold percentage to require conversion of shares			4.90%

Stockholder's Equity - Common U

Stockholder's Equity - Common Units Outstanding (Details) - Tradeweb Markets LLC - shares	Apr. 04, 2019	Dec. 31, 2019
LLC Interests
Class of Stock [Line Items]
Common units exchanged	222,222,197
Class A common stock
Class of Stock [Line Items]
Common units exchanged		146,333
Class C common stock
Class of Stock [Line Items]
Common units exchanged		447
Class P(A) Shares
Class of Stock [Line Items]
Common units exchanged		6,887
Class P(C) Shares
Class of Stock [Line Items]
Common units exchanged		2
Class P-1(A) Shares
Class of Stock [Line Items]
Common units exchanged		6,094
Class P-1(C) Shares
Class of Stock [Line Items]
Common units exchanged		232

Stockholder's Equity - Issuance

Stockholder's Equity - Issuance and Cancellation of Common Stock (Details) - shares	Apr. 08, 2019	Jun. 30, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Shares contributed by Refinitiv Owner		96,933,192
Continuing LLC Owners
Class of Stock [Line Items]
Percentage of combined voting power	27.50%
Refinitiv Direct Owner [Member]
Class of Stock [Line Items]
Shares contributed by Refinitiv Owner	96,933,192
Class A common stock
Class of Stock [Line Items]
Number of shares owned	46,000,000
Percentage of combined voting power	2.70%
Class B common stock
Class of Stock [Line Items]
Shares contributed by Refinitiv Owner	96,933,192
Number of shares canceled	9,993,731
Class B common stock | Refinitiv Direct Owner [Member]
Class of Stock [Line Items]
Number of shares owned	96,933,192
Percentage of combined voting power	56.40%
Class C common stock
Class of Stock [Line Items]
Shares issued to acquire TWM LLC	20,000,000
Number of shares canceled	9,993,731
Class C common stock | Continuing LLC Owners
Class of Stock [Line Items]
Number of shares owned	10,006,269
Class D common stock
Class of Stock [Line Items]
Shares issued to acquire TWM LLC	105,289,005
Number of shares canceled	36,006,269
Class D common stock | Continuing LLC Owners
Class of Stock [Line Items]
Number of shares owned	46,294,407
Class D common stock | Refinitiv LLC Owner [Member]
Class of Stock [Line Items]
Percentage of combined voting power	13.40%
Number of LLC Interest	22,988,329
Tradeweb Markets LLC
Class of Stock [Line Items]
Number of LLC Interest			59,182,155
Ownership percentage, Continuing LLC Owners			26.60%
Number of LLC Interest held by parent	142,933,192		163,341,520
Ownership interest	64.30%		73.40%
Tradeweb Markets LLC | Continuing LLC Owners
Class of Stock [Line Items]
Number of LLC Interest	56,300,676
Ownership percentage, Continuing LLC Owners	25.30%
Tradeweb Markets LLC | Class A common stock
Class of Stock [Line Items]
Percentage of economic interest	20.70%
Tradeweb Markets LLC | Class B common stock | Refinitiv Direct Owner [Member]
Class of Stock [Line Items]
Percentage of economic interest	43.60%
Tradeweb Markets LLC | Class D common stock | Refinitiv LLC Owner [Member]
Class of Stock [Line Items]
Number of LLC Interest	22,988,329
Ownership percentage, Continuing LLC Owners	10.30%

Stockholder's Equity - Redempti

Stockholder's Equity - Redemptions and Exchange of LLC Interests (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 08, 2019	Oct. 31, 2019	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2019
Subsidiary, Sale of Stock [Line Items]
Weighted Weighted Average Share Price			$ 21.62	$ 21.62	$ 21.62
LLC units | October 2019 Follow-On Offering
Subsidiary, Sale of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares		19,835,666
LLC units | Redemptions and Exchanges of LLC Interests [Member]
Subsidiary, Sale of Stock [Line Items]
Number of LLC Units received from the exchange transaction					271,184
Class A common stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)				46,000,000
Class A common stock | October 2019 Follow-On Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)			19,881,059
Weighted Weighted Average Share Price		$ 42
Net proceeds		$ 810
Stock Repurchased and Retired During Period, Shares		45,393
Class A common stock | Redemptions and Exchanges of LLC Interests [Member]
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)					271,184
Class D common stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)				69,282,736
Class D common stock | Redemptions and Exchanges of LLC Interests [Member]
Subsidiary, Sale of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares					271,184
Class B common stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)	96,933,192			96,933,192
Class C common stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)				10,006,269
Tradeweb Markets LLC
Subsidiary, Sale of Stock [Line Items]
Weighted Weighted Average Share Price	$ 27
Net proceeds	$ 1,200
Ownership interest	64.30%		73.40%	73.40%	73.40%
Equity interest of noncontrolling shareholders in consolidated entity			26.60%	26.60%	26.60%
Tradeweb Markets LLC | Public Investors
Subsidiary, Sale of Stock [Line Items]
Equity interest of noncontrolling shareholders in consolidated entity			29.80%	29.80%	29.80%
Tradeweb Markets LLC | Bank Stockholders
Subsidiary, Sale of Stock [Line Items]
Equity interest of noncontrolling shareholders in consolidated entity			16.20%	16.20%	16.20%
Tradeweb Markets Inc | Public Investors
Subsidiary, Sale of Stock [Line Items]
Voting power percentage			4.30%	4.30%	4.30%
Tradeweb Markets Inc | Bank Stockholders
Subsidiary, Sale of Stock [Line Items]
Voting power percentage			18.40%	18.40%	18.40%
Tradeweb Markets Inc | Class A common stock | Public Investors
Subsidiary, Sale of Stock [Line Items]
Number of share owned			66,408,328	66,408,328	66,408,328
Tradeweb Markets Inc | Class D common stock | Bank Stockholders
Subsidiary, Sale of Stock [Line Items]
Number of share owned			27,662,354	27,662,354	27,662,354
Tradeweb Markets Inc | Class C common stock | Bank Stockholders
Subsidiary, Sale of Stock [Line Items]
Number of share owned			8,328,983	8,328,983	8,328,983
Tradeweb Markets LLC
Subsidiary, Sale of Stock [Line Items]
Weighted Weighted Average Share Price	$ 27
Net proceeds	$ 1,200
Refinitiv | Tradeweb Markets LLC
Subsidiary, Sale of Stock [Line Items]
Ownership interest			53.90%	53.90%	53.90%
Refinitiv | Tradeweb Markets Inc
Subsidiary, Sale of Stock [Line Items]
Ownership interest			77.20%	77.20%	77.20%
Refinitiv | Tradeweb Markets Inc | Class D common stock
Subsidiary, Sale of Stock [Line Items]
Number of share owned			22,988,329	22,988,329	22,988,329
Refinitiv | Tradeweb Markets Inc | Class B common stock
Subsidiary, Sale of Stock [Line Items]
Number of share owned			96,933,192	96,933,192	96,933,192

Non-Controlling Interests (Deta

Non-Controlling Interests (Details) $ in Thousands	Apr. 08, 2019shares	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019USD ($)shares	Dec. 31, 2018	Dec. 31, 2017
Non-Controlling Interests
Financial Designation, Predecessor and Successor [Fixed List]		Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Net income attributable to Tradeweb Markets Inc.						$ 83,769
Allocation of equity to non-controlling interests arising from the reorganization transactions and IPO						(1,607,529)
Change in ownership percentage resulting from follow-on offering and issuance of common stock from equity incentive plans						402,227
Net transfers (to) from non-controlling interests						(1,205,302)
Change from net income attributable to Tradeweb Markets Inc. and transfers (to) from non-controlling interests						$ (1,121,533)
Class A common stock
Non-Controlling Interests
Conversion ratio						1
Class B common stock
Non-Controlling Interests
Conversion ratio						1
Tradeweb Markets LLC
Non-Controlling Interests
Number of LLC Interests held by Tradeweb Markets Inc. | shares	142,933,192					163,341,520
Number of LLC Interests held by non-controlling interests | shares						59,182,155
Total LLC Interests outstanding | shares						222,523,675
Number of LLC Interests held by Tradeweb Markets Inc.	64.30%			73.40%		73.40%
Equity interest of noncontrolling shareholders in consolidated entity				26.60%		26.60%
Total LLC Interests outstanding				100.00%		100.00%

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019USD ($)employeeshares	Sep. 30, 2018	Dec. 31, 2019USD ($)employeeshares	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Percentage of performance modifier					100.00%
Number of employees impacted | employee			54		54
Amount reclassified to members capital | $			$ 20,718		$ 19,100
Exercise period following a change in control					15 days
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of performance modifier					200.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of performance modifier					0.00%
Equity-settled PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial Designation, Predecessor and Successor [Fixed List]					Successor
Equity settled PRSU's issued on conversion			2,000,384		2,000,384
Cash-settled PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash settled PRSU's converted					1,033.2
Total fair value of vested PRSUs | $					$ 17,200
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial Designation, Predecessor and Successor [Fixed List]					Successor
2019 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized			8,841,864		8,841,864
Cliff vesting period					10 years
Vesting period					10 years
Based solely on the passage of time | Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						50.00%
If the Company achieves certain performance targets | Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period						4 years
Vesting period						4 years

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - (PRSUs settlement) (Details)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Equity-settled PRSUs
PRSUs
Balance outstanding at beginning of period (in units) | shares	2,000,384
Grants (in units) | shares	781,026
Performance adjustment (in units) | shares	762,326
Forfeitures (in units) | shares	(53,070)
Balance options outstanding at end of period (in units) | shares	3,490,666
Weighted Average Grant-Date Fair Value
Balance outstanding at beginning of period (in dollars per unit) | $ / shares	$ 9.53
Grants (in dollars per unit) | $ / shares	21.08
Performance adjustment (in dollars per unit) | $ / shares	21.08
Forfeitures (in dollars per unit) | $ / shares	13.48
Balance outstanding at end of period (in dollars per unit) | $ / shares	$ 14.59
Cash-settled PRSUs
PRSUs
Balance outstanding at beginning of period (in units) | shares	522
Vests (in units) | shares	(507)
Balance options outstanding at end of period (in units) | shares	15
Weighted Average Grant-Date Fair Value
Balance outstanding at beginning of period (in dollars per unit) | $ / shares	$ 34,221
Vests (in dollars per unit) | $ / shares	33,842
Balance outstanding at end of period (in dollars per unit) | $ / shares	$ 94,997

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - PSRUs-settled activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-Based Compensation Plans
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Compensation expense		$ 9,400		$ 15,900	$ 50,700		$ 26,100
Equity-settled PRSUs
Share-Based Compensation Plans
Financial Designation, Predecessor and Successor [Fixed List]					Successor
Compensation expense					$ 25,392
Income tax benefit					$ 4,781
Options
Share-Based Compensation Plans
Financial Designation, Predecessor and Successor [Fixed List]					Successor
Compensation expense					$ 24,432
Income tax benefit					$ (8,556)

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options
Options outstanding at beginning of period (in shares)			18,091,793
Grants (in shares)			886,115
Exercises (in shares)			(984,585)
Forfeitures and adjustments (in shares)			(253,579)
Options outstanding at end of period (in shares)	18,091,793		17,739,744	18,091,793
Vested options outstanding			8,061,312	0
Weighted Average Grant Date Fair Value
Options outstanding at beginning of period (in dollars per share)			$ 1.85
Grants (in dollars per share)			8.83
Exercises (in dollars per share)			1.80
Forfeitures and adjustments (in dollars per share)			2.67
Options outstanding at end of period (in dollars per share)	$ 1.85		2.19	$ 1.85
Vested options outstanding (in dollars per share)			$ 1.80
Options exercised, intrinsic value			$ 21,300
Exercisable	0			0
Compensation expense	$ 9,400	$ 15,900	50,700		$ 26,100
Options
Weighted Average Grant Date Fair Value
Compensation expense			24,432
Initial Public Offering
Weighted Average Grant Date Fair Value
Compensation expense			$ 18,900

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Assumptions (Details)	12 Months Ended
	Dec. 31, 2019$ / shares
Stock-Based Compensation Plans
Weighted Average Expected Life (years)	5 years 8 months 12 days
Weighted Average Risk Free Interest Rate	2.90%
Weighted Average Expected Volatility	20.00%
Weighted Average Expected Dividend Yield	3.90%
Weighted Weighted Average Share Price	$ 21.62
Weighted Average Exercise Price	$ 21.62

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Compensation expense (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2017
Stock-Based Compensation Plans
Compensation expense	$ 9.4	$ 15.9	$ 50.7	$ 26.1

Stock-Based Compensation Plan_8

Stock-Based Compensation Plans - unrecognized compensation expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Cash-settled PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 383
Weighted average recognition period	1 year
Equity-settled PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 31,283
Weighted average recognition period	1 year 8 months 12 days
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 4,068
Weighted average recognition period	2 years 9 months 18 days

Related Party Transactions - Ba

Related Party Transactions - Balances (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transactions
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Cash and cash equivalents		$ 283,790				$ 283,790
Receivables from brokers and dealers and clearing organizations		3,332				3,332
Deposits with clearing organizations		500				500
Accounts receivable		40,730				40,730
Receivable from affiliates		3,243	$ 2,525		$ 2,525	3,243
Other assets		9				9
Payable to brokers and dealers and clearing organizations		2,404				2,404
Deferred revenue		9,151	4,733		4,733	9,151
Payable to affiliates		$ 5,009	$ 1,506		$ 1,506	$ 5,009

Related Party Transactions - Co

Related Party Transactions - Consolidated Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transactions
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Revenue:
Revenue		$ 178,637		$ 478,941	$ 775,566		$ 504,448
Shared Services Fees:
Technology and communications		9,907		26,598	39,285		30,013
General and administrative		11,837		23,056	34,960		33,973
Occupancy		$ 3,308		$ 10,732	$ 14,686		$ 14,441
Affiliated Entity
Related Party Transactions
Financial Designation, Predecessor and Successor [Fixed List]		Successor		Predecessor	Successor		Predecessor
Operating Income:
Net interest income (expense)		$ 17		$ 34	$ 858		$ (415)
Shared Services Fees:
Technology and communications		740		2,220	2,960		2,960
General and administrative		180		539	430		719
Occupancy		155		466	481		621
Transaction fees | Affiliated Entity
Revenue:
Revenue		59,259		159,663	59,643		151,695
Subscription fees | Affiliated Entity
Revenue:
Revenue		5,718		16,627	5,670		37,426
Commissions | Affiliated Entity
Revenue:
Revenue		12,401		34,944	16,186		43,315
Refinitiv market data fees | Affiliated Entity
Revenue:
Revenue		$ 13,467		$ 36,851	$ 55,635		$ 50,125

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2017	Dec. 31, 2014
Related Party Transactions
Other assets	$ 25,027		$ 27,236
Contingent consideration recognized		$ 26,830		$ 58,520
Refinitiv
Related Party Transactions
Other assets			2,700
Refinitiv | Operating Expense Reimbursement
Related Party Transactions
Related party expense	$ 3,800		$ 6,700
TR | Operating Expense Reimbursement
Related Party Transactions
Related party expense		$ 28,700		$ 38,400
Banks
Related Party Transactions
Capital contribution					$ 120,000
Employees
Related Party Transactions
Investment by employees					$ 5,300

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value of Financial Instruments
Total assets measured at fair value	$ 219,158	$ 127,927
Money market funds
Fair Value of Financial Instruments
Money market funds	219,158	127,927
Level 1
Fair Value of Financial Instruments
Total assets measured at fair value	219,158	127,927
Level 1 | Money market funds
Fair Value of Financial Instruments
Money market funds	$ 219,158	$ 127,927

Credit Risk (Details)

Credit Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Credit Risk
Allowance for doubtful accounts	$ 200	$ 1,200
Total stockholder's equity	3,378,588	$ 4,572,334
Excess Capital	10,000
Minimum
Credit Risk
Total stockholder's equity	$ 25,000

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Apr. 08, 2019USD ($)	Dec. 31, 2019USD ($)action
Litigation relating to distribution of financial strength ratings
Commitments and Contingencies
Damages sought		$ 80
Litigation relating to distribution of financial strength ratings | Minimum
Commitments and Contingencies
Damages sought		4
Litigation relating to distribution of financial strength ratings | Maximum
Commitments and Contingencies
Damages sought		$ 8
Antitrust Actions Related To Trading Practices
Commitments and Contingencies
Number of actions | action		2
Revolving credit facility
Commitments and Contingencies
Term of debt	5 years
Maximum borrowing capacity	$ 500
Commitment fee (as a percent)	0.25%
Amount outstanding		$ 0
Revolving credit facility | Federal funds
Commitments and Contingencies
Spread (as a percent)	0.50%
Revolving credit facility | One-month LIBOR
Commitments and Contingencies
Spread (as a percent)	1.00%
Revolving credit facility | Base rate
Commitments and Contingencies
Spread (as a percent)	0.75%
Revolving credit facility | LIBOR
Commitments and Contingencies
Spread (as a percent)	1.75%
Floor (as a percent)	0.00%

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Income Per Share
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor				Successor	Predecessor	Successor	Successor	Predecessor
Numerator:
Pre-IPO net income attributable to Tradeweb Markets LLC								$ 83,769
Denominator:
Weighted average outstanding - Basic		222,221,628					215,365,920	148,013,274		215,568,635
Weighted average outstanding - Diluted		222,243,851					215,365,920	156,540,246		215,568,635
Earnings per share - Basic								$ 0.57
Earnings per share - Diluted								$ 0.54
Shares excluded from computation of diluted earnings per share							5,444,566
PRSU
Denominator:
Dilutive effect								2,464,137
Options
Net Income Per Share
Financial Designation, Predecessor and Successor [Fixed List]								Successor
Denominator:
Dilutive effect								6,062,835
Potential Dilutive
Denominator:
Shares excluded from computation of diluted earnings per share								59,182,155
Tradeweb Markets LLC
Net Income Per Share
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Predecessor	Predecessor	Predecessor
Numerator:
Pre-IPO net income attributable to Tradeweb Markets LLC	$ 42,352	$ 29,307					$ 130,160	$ 42,352		$ 83,648
Denominator:
Weighted average outstanding - Basic	222,222,197	222,221,628	219,165,997	213,435,314	213,435,321		215,365,920	222,222,197		212,568,635
Weighted average outstanding - Diluted	223,320,457	222,243,851	219,165,997	213,435,314	213,435,321		215,365,920	223,320,457		212,568,635
Earnings per share - Basic	$ 0.19	$ 0.13	$ 0.21	$ 0.18	$ 0.21		$ 0.60	$ 0.19		$ 0.39
Earnings per share - Diluted	$ 0.19	$ 0.13	$ 0.21	$ 0.18	$ 0.21		$ 0.60	$ 0.19		$ 0.39
Shares excluded from computation of diluted earnings per share								128,125
Tradeweb Markets LLC | PRSU
Denominator:
Dilutive effect	1,098,260	22,223

Regulatory Capital Requiremen_3

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
TWL
Regulatory Capital Requirements
Regulatory Capital	$ 42,317	$ 18,986
Regulatory Capital Requirement	2,396	2,698
Excess Regulatory Capital	39,921	16,288
DW
Regulatory Capital Requirements
Regulatory Capital	52,016	41,164
Regulatory Capital Requirement	2,026	1,803
Excess Regulatory Capital	49,990	39,361
TWD
Regulatory Capital Requirements
Regulatory Capital	33,807	24,042
Regulatory Capital Requirement	664	599
Excess Regulatory Capital	33,143	23,443
TEL
Regulatory Capital Requirements
Regulatory Capital	49,611	46,157
Regulatory Capital Requirement	21,856	17,493
Excess Regulatory Capital	27,755	28,664
TWJ
Regulatory Capital Requirements
Regulatory Capital	11,851	10,592
Regulatory Capital Requirement	8,565	3,413
Excess Regulatory Capital	3,286	7,179
TWEU
Regulatory Capital Requirements
Regulatory Capital	6,217
Regulatory Capital Requirement	1,701
Excess Regulatory Capital	4,516
TW SEF
Regulatory Capital Requirements
Financial Resources	21,303	31,232
Required Financial Resources	10,500	10,500
Excess Financial Resources	10,803	20,732
Liquid Financial Assets	18,168	16,662
Required Liquid Financial Assets	5,250	5,250
Excess Liquid Financial Assets	12,918	11,412
DW SEF
Regulatory Capital Requirements
Financial Resources	13,707	17,837
Required Financial Resources	5,505	5,169
Excess Financial Resources	8,202	12,668
Liquid Financial Assets	7,583	11,888
Required Liquid Financial Assets	2,753	2,585
Excess Liquid Financial Assets	$ 4,830	$ 9,303

Business Segment and Geograph_3

Business Segment and Geographic Information - Revenue by Client Sector (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Segment and Geographic Information
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Gross revenues		$ 178,637		$ 505,771	$ 775,566		$ 562,968
Contingent consideration				(26,830)			(58,520)
Net revenue		178,637		478,941	775,566		504,448
Operating expenses		146,702		338,607	585,747		415,356
Operating income		31,935		140,334	189,819		89,092
Institutional
Business Segment and Geographic Information
Gross revenues		103,971		301,918	453,379		318,038
Wholesale
Business Segment and Geographic Information
Gross revenues		38,153		99,028	171,096		118,451
Retail
Business Segment and Geographic Information
Gross revenues		19,780		57,766	80,368		70,857
Market Data
Business Segment and Geographic Information
Gross revenues		$ 16,733		$ 47,059	$ 70,723		$ 55,622

Business Segment and Geograph_4

Business Segment and Geographic Information - Revenue and Long-lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Segment and Geographic Information
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor	Predecessor	Successor	Successor	Predecessor
Gross revenues		$ 178,637		$ 505,771	$ 775,566		$ 562,968
Contingent consideration				(26,830)			(58,520)
Net revenue		178,637		478,941	775,566		504,448
Long-lived assets		4,284,355	$ 4,214,233		4,214,233	$ 4,284,355
U.S.
Business Segment and Geographic Information
Gross revenues		115,907		324,304	497,316		385,176
Long-lived assets		4,276,568	4,200,133		4,200,133	4,276,568
International
Business Segment and Geographic Information
Gross revenues		62,730		$ 181,467	278,250		$ 177,792
Long-lived assets		$ 7,787	$ 14,100		$ 14,100	$ 7,787

Quarterly Results of Operatio_3

Quarterly Results of Operations (Unaudited) - Operating results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Apr. 08, 2019
Revenues
Financial Designation, Predecessor and Successor [Fixed List]				Successor		Successor				Successor	Predecessor	Successor	Successor	Predecessor
Gross revenue						$ 178,637					$ 505,771	$ 775,566		$ 562,968
Contingent consideration											(26,830)			(58,520)
Net revenue						178,637					478,941	775,566		504,448
Expenses
Employee compensation and benefits						80,436					209,053	329,457		248,963
Depreciation and amortization						33,020					48,808	139,330		68,615
Technology and communications						9,907					26,598	39,285		30,013
General and administrative						11,837					23,056	34,960		33,973
Professional fees						8,194					20,360	28,029		19,351
Occupancy						3,308					10,732	14,686		14,441
Total expenses						146,702					338,607	585,747		415,356
Operating income						31,935					140,334	189,819		89,092
Tax receivable agreement liability adjustment	$ 240,817									$ 240,817		240,817			$ 171,400
Net interest income						787					1,726	2,373		685
Income before taxes						32,722					142,060	225,326		89,777
Provision for income taxes						(3,415)					(11,900)	(52,302)		(6,129)
Net income				$ 42,352	$ 29,307	$ 29,307				130,672	$ 130,160	173,024		$ 83,648
Net income attributable to non-controlling interests												46,903
Net income attributable to Tradeweb Markets Inc.												$ 83,769
Earnings per share
Basic												$ 0.57
Diluted												$ 0.54
Weighted average shares outstanding
Basic						222,221,628					215,365,920	148,013,274		215,568,635
Diluted						222,243,851					215,365,920	156,540,246		215,568,635
Transaction fees
Revenues
Gross revenue						$ 97,130					$ 273,751	$ 423,583		$ 267,020
Subscription fees
Revenues
Gross revenue						33,052					107,130	138,731		144,409
Commissions
Revenues
Gross revenue						32,840					79,830	149,365		96,745
Refinitiv market data fees
Revenues
Gross revenue						13,467					36,851	55,635		50,125
Other
Revenues
Gross revenue						$ 2,148					8,209	8,252		4,669
Tradeweb Markets Inc
Revenues
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Successor	Successor
Gross revenue	$ 197,308	$ 200,981	$ 190,485
Net revenue	197,308	200,981	190,485
Expenses
Employee compensation and benefits	76,545	79,644	95,995
Depreciation and amortization	36,402	35,133	34,292
Technology and communications	10,199	9,527	9,519
General and administrative	8,999	7,507	9,365
Professional fees	7,048	7,272	6,738
Occupancy	3,786	3,640	3,621
Total expenses	142,979	142,723	159,530
Operating income	54,329	58,258	30,955
Tax receivable agreement liability adjustment	33,134									$ 33,134		33,134
Net interest income	704	636	175
Income before taxes	88,167	58,894	31,130
Provision for income taxes	(30,889)	(10,316)	(6,314)
Net income	57,278	48,578	24,816
Net income attributable to non-controlling interests	15,949	18,966	11,988
Net income attributable to Tradeweb Markets Inc.	$ 41,329	$ 29,612	$ 12,828
Earnings per share
Basic	$ 0.26	$ 0.21	$ 0.09
Diluted	$ 0.25	$ 0.20	$ 0.09
Weighted average shares outstanding
Basic	157,950,550	142,935,206	142,933,192
Diluted	167,323,520	151,362,643	150,847,183
Tradeweb Markets Inc | Transaction fees
Revenues
Gross revenue	$ 104,245	$ 112,746	$ 103,952
Tradeweb Markets Inc | Subscription fees
Revenues
Gross revenue	34,333	35,387	34,566
Tradeweb Markets Inc | Commissions
Revenues
Gross revenue	41,165	37,590	36,413
Tradeweb Markets Inc | Refinitiv market data fees
Revenues
Gross revenue	15,383	13,251	13,385
Tradeweb Markets Inc | Other
Revenues
Gross revenue	$ 2,182	$ 2,007	$ 2,169
Tradeweb Markets LLC
Revenues
Financial Designation, Predecessor and Successor [Fixed List]				Successor		Successor	Predecessor	Predecessor	Predecessor
Gross revenue				$ 186,792		$ 178,637	$ 165,253	$ 171,015	$ 169,503
Contingent consideration							2,537	(19,297)	(10,070)
Net revenue				186,792		178,637	167,790	151,718	159,433
Expenses
Employee compensation and benefits				77,273		80,436	69,076	68,407	71,570
Depreciation and amortization				33,503		33,020	16,362	16,178	16,268
Technology and communications				10,040		9,907	9,112	9,023	8,463
General and administrative				9,089		11,837	9,386	7,153	6,517
Professional fees				6,971		8,194	7,546	7,276	5,538
Occupancy				3,639		3,308	3,491	3,519	3,722
Total expenses				140,515		146,702	114,973	111,556	112,078
Operating income				46,277		31,935	52,817	40,162	47,355
Net interest income				858		787	673	582	471
Income before taxes				47,135		32,722	53,490	40,744	47,826
Provision for income taxes				(4,783)		(3,415)	(7,535)	(1,847)	(2,518)
Net income				$ 42,352		29,307	$ 45,955	$ 38,897	$ 45,308
Net income attributable to Tradeweb Markets Inc.						$ 29,307					$ 130,160	$ 42,352		$ 83,648
Earnings per share
Basic				$ 0.19		$ 0.13	$ 0.21	$ 0.18	$ 0.21		$ 0.60	$ 0.19		$ 0.39
Diluted				$ 0.19		$ 0.13	$ 0.21	$ 0.18	$ 0.21		$ 0.60	$ 0.19		$ 0.39
Weighted average shares outstanding
Basic				222,222,197		222,221,628	219,165,997	213,435,314	213,435,321		215,365,920	222,222,197		212,568,635
Diluted				223,320,457		222,243,851	219,165,997	213,435,314	213,435,321		215,365,920	223,320,457		212,568,635
Tradeweb Markets LLC | Transaction fees
Revenues
Gross revenue				$ 102,640		$ 97,130	$ 92,582	$ 91,030	$ 90,139
Tradeweb Markets LLC | Subscription fees
Revenues
Gross revenue				34,445		33,052	33,157	37,647	36,326
Tradeweb Markets LLC | Commissions
Revenues
Gross revenue				34,197		32,840	24,394	27,553	27,883
Tradeweb Markets LLC | Refinitiv market data fees
Revenues
Gross revenue				13,616		13,467	12,533	12,081	12,237
Tradeweb Markets LLC | Other
Revenues
Gross revenue				$ 1,894		$ 2,148	$ 2,587	$ 2,704	$ 2,918

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event	3 Months Ended
	Mar. 31, 2020USD ($)
Class A common stock
Subsequent Event [Line Items]
Cash dividend declared	$ 0.08
Class B common stock
Subsequent Event [Line Items]
Cash dividend declared	$ 0.08