Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Valuation of Company's Assets and Liabilities Measured at Fair Value

The following table summarizes the valuation of the Company’s assets and liabilities measured at fair value as categorized based on the hierarchy described in Note 2:

	Level 1		Level 2		Level 3		Total
	(In thousands)
As of June 30, 2024
Assets
Money market funds	$	25,220	$	—	$	—	$	25,220
Securities available-for-sale
Corporate debt		—		25,198		—		25,198
Trading securities
U.S. Treasuries		—		99,527		—		99,527
Mutual funds held in rabbi trust		—		11,183		—		11,183
Foreign currency forward position		—		500		—		500
Total assets	$	25,220	$	136,408	$	—	$	161,628
Liabilities
Securities sold, not yet purchased		—		9,167		—		9,167
Total liabilities	$	—	$	9,167	$	—	$	9,167
As of December 31, 2023
Assets
Money market funds	$	18,634	$	—	$	—	$	18,634
Securities available-for-sale
Corporate debt		—		24,694		—		24,694
Trading securities
U.S. Treasuries		—		99,682		—		99,682
Mutual funds held in rabbi trust		—		10,485		—		10,485
Foreign currency forward position		—		1,901		—		1,901
Total assets	$	18,634	$	136,762	$	—	$	155,396

Carrying Value of Financial Asset and Liability Not Measured at Fair Value

The table below presents the carrying value, fair value and fair value hierarchy category of the Company's financial assets and liabilities that are not measured at fair value on the Consolidated Statements of Financial Condition. The carrying values of the Company's financial assets and liabilities not measured at fair value categorized in the fair value hierarchy as Level 1 and Level 2 approximate fair value due to the short-term nature of the underlying assets and liabilities.

	Carrying Value		Fair Value		Level 1		Level 2		Level 3		Total
	(In thousands)
As of June 30, 2024
Financial assets not measured at fair value:
Cash	$	408,843	$	408,843	$	408,843	$	—	$	—	$	408,843
Cash segregated under federal regulations		46,141		46,141		46,141		—		—		46,141
Accounts receivable, net of allowance		92,350		92,350		—		92,350		—		92,350
Receivables from broker-dealers, clearing    organizations and customers		577,992		577,992		93,754		484,238		—		577,992
Total	$	1,125,326	$	1,125,326	$	548,738	$	576,588	$	—	$	1,125,326
Financial liabilities not measured at fair value:
Payables to broker-dealers, clearing    organizations and customers	$	392,846	$	392,846	$	—	$	392,846	$	—	$	392,846
As of December 31, 2023
Financial assets not measured at fair value:
Cash	$	432,646	$	432,646	$	432,646	$	—	$	—	$	432,646
Cash segregated under federal regulations		45,122		45,122		45,122		—		—		45,122
Accounts receivable, net of allowance		89,839		89,839		—		89,839		—		89,839
Receivables from broker-dealers, clearing    organizations and customers		687,936		687,936		115,151		572,785		—		687,936
Total	$	1,255,543	$	1,255,543	$	592,919	$	662,624	$	—	$	1,255,543
Financial liabilities not measured at fair value:
Payables to broker-dealers, clearing    organizations and customers	$	537,398	$	537,398	$	—	$	537,398	$	—	$	537,398

Summary of Foreign Currency Forward Contracts

The following table summarizes the Company’s foreign currency forward position:

	As of
	June 30, 2024		December 31, 2023
	(In thousands)
Notional value	$	62,730	$	61,858
Fair value of notional		63,230		63,759
Fair value of the asset	$	500	$	1,901

Summary of Company's Investments and Securities Positions

The following table summarizes the Company’s investments and securities positions:

	Amortized cost			Gross unrealized gains		Gross unrealized losses			Fair value
		(In thousands)
As of June 30, 2024
Securities available-for-sale
Corporate debt	$		25,300	$	19	$	(121	)	$	25,198
Trading securities
U.S. Treasuries			99,877		—		(350	)		99,527
Mutual funds held in rabbi trust			10,315		878		(10	)		11,183
Total investments	$		135,492	$	897	$	(481	)	$	135,908
Securities sold, not yet purchased
U.S. Treasuries	$		9,211	$	44	$	—		$	9,167
As of December 31, 2023
Securities available-for-sale
Corporate debt	$		24,705	$	55	$	(66	)	$	24,694
Trading securities
U.S. Treasuries			99,236		446		—			99,682
Mutual funds held in rabbi trust			10,962		172		(649	)		10,485
Total investments	$		134,903	$	673	$	(715	)	$	134,861

Summary of Companies Unrealized and Realized Gains and Losses on Investments

The following table summarizes the Company’s unrealized and realized gains and losses on investments:

	Three Months Ended June 30,						Six Months Ended June 30,
	2024			2023			2024			2023
	(In thousands)
Unrealized gains/(losses)
Securities available-for-sale
Corporate debt	$	(18	)	$	(168	)	$	(91	)	$	(223	)
Trading securities
U.S. Treasuries		262			(766	)		7			(346	)
Mutual funds held in rabbi trust		671			520			1,345			1,105
Total investments	$	915		$	(414	)	$	1,261		$	536
Liabilities:
Securities sold, not yet purchased	$	44		$	—		$	44		$	—
Realized gains/(losses)
Securities available-for-sale
Corporate debt	$	—		$	—		$	2		$	(17	)
Trading securities
Mutual funds held in rabbi trust		(412	)		(59	)		(377	)		(59	)
Total investments	$	(412	)	$	(59	)	$	(375	)	$	(76	)

Summary of Fair Value of Investments Based upon Contractual Maturities

The following table summarizes the fair value of the investments based upon the contractual maturities:

	Less than one year		Due in 1 - 5 years		Total
	(In thousands)
As of June 30, 2024
Securities available-for-sale
Corporate debt	$	10,637	$	14,561	$	25,198
Trading securities
U.S. Treasuries		74,615		24,912		99,527
Mutual funds held in rabbi trust		11,183		—		11,183
Total	$	96,435	$	39,473	$	135,908
As of December 31, 2023
Securities available-for-sale
Corporate debt	$	10,727	$	13,967	$	24,694
Trading securities
U.S. Treasuries		49,756		49,926		99,682
Mutual funds held in rabbi trust		10,485		—		10,485
Total	$	70,968	$	63,893	$	134,861

Summary of Fair Values and Unrealized Losses on Investments

The following table provides fair values and unrealized losses on the Company’s available-for-sale investments and the aging of securities’ continuous unrealized loss positions:

	Less than Twelve Months					Twelve Months or More					Total
	Fair value		Gross unrealized losses			Fair value		Gross unrealized losses			Fair value		Gross unrealized losses
	(In thousands)
As of June 30, 2024
Corporate debt	$	8,645	$	(41	)	$	11,635	$	(79	)	$	20,280	$	(121	)
As of December 31, 2023
Corporate debt	$	17,658	$	(66	)	$	—	$	—		$	17,658	$	(66	)