Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2025

Accounting Policies [Abstract]

Summary of Commission Revenue by Fee Type

The following table presents commission revenue by fee type:

		Three Months Ended June 30,					Six Months Ended June 30,
		2025			2024		2025		2024
	(In thousands)
Commission revenue by fee type
Variable transaction fees
Disclosed trading	$		98,088	$		86,778	$	193,543	$	181,556
Open Trading – matched principal trading			47,319			42,439		90,371		90,619
U.S. government bonds - matched principal trading			5,329			4,147		9,858		7,859
Other			7,337			5,076		12,292		9,925
Total variable transaction fees			158,073			138,440		306,064		289,959
Distribution fees and unused minimum fees			33,697			33,239		67,049		66,593
Total commissions	$		191,770	$		171,679	$	373,113	$	356,552

Summary of Information Services Revenue by Timing of Recognition

The following table presents information services revenue by timing of recognition:

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
	(In thousands)
Information services revenue by timing    of recognition
Services transferred over time	$	12,856	$	12,103	$	25,554	$	23,977
Services transferred at a point in time		231		441		437		448
Total information services revenues	$	13,087	$	12,544	$	25,991	$	24,425

Summary of Post-Trade Services Revenue by Timing of Recognition

The following table presents post-trade services revenue by timing of recognition:

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
	(In thousands)
Post-trade services revenue by timing    of recognition
Services transferred over time	$	11,039	$	10,358	$	22,089	$	20,898
Services transferred at a point in time		37		42		75		232
Total post-trade services revenues	$	11,076	$	10,400	$	22,164	$	21,130

Summary of Technology Services Revenue by Timing of Recognition

The following table presents technology services revenue by timing of recognition:

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
	(In thousands)
Technology services revenue by timing    of recognition
Services transferred over time	$	3,289	$	3,024	$	6,351	$	5,853
Services transferred at a point in time		240		13		419		18
Total technology services revenues	$	3,529	$	3,037	$	6,770	$	5,871

Summary of Revenue Recognized from Contract Liabilities and Remaining Balance

The revenue recognized from contract liabilities and the remaining balance is shown below:

	December 31, 2024			Payments received in advance of services to be performed		Revenue recognized for services performed during the period			Foreign Currency Translation		June 30, 2025
		(In thousands)
Information services	$		3,302	$	7,045	$	(7,343	)	$	—	$	3,004
Post-trade services			1,286		13,349		(14,753	)		118		—
Technology services			415		3,937		(4,034	)		—		318
Total deferred revenue	$		5,003	$	24,331	$	(26,130	)	$	118	$	3,322