Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

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

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

	Level 1		Level 2		Level 3		Total
	(In thousands)
As of December 31, 2022
Assets
Money market funds	$	59,173	$	—	$	—	$	59,173
Trading securities
U.S. Treasuries		—		74,409		—		74,409
Mutual funds held in rabbi trust		—		9,383		—		9,383
Total assets	$	59,173	$	83,792	$	—	$	142,965
Liabilities
Contingent consideration payable	$	—	$	—	$	12,340	$	12,340
Foreign currency forward position		—		1,688		—		1,688
Total liabilities	$	—	$	1,688	$	12,340	$	14,028
As of December 31, 2021
Assets
Money market funds	$	14,206	$	—	$	—	$	14,206
Trading securities
U.S. Treasuries		—		24,883		—		24,883
Mutual funds held in rabbi trust		—		11,195		—		11,195
Total assets	$	14,206	$	36,078	$	—	$	50,284
Liabilities
Contingent consideration payable	$	—	$	—	$	41,090	$	41,090

Summary of the Change in the Company's Contingent Consideration Payable

The following table summarizes the change in the Company's Level 3 liabilities for the year ended December 31, 2022:

	December 31, 2021		Payments			Unrealized (Gain)/Loss		Realized (Gain)/Loss			Foreign Currency Translation			December 31, 2022
	(In thousands)
Contingent consideration payable	$	41,090	$	(26,164	)	$	532	$	(1,769	)	$	(1,349	)	$	12,340

The table below presents the range and average significant unobservable inputs used in the valuation of the Company's Level 3 liabilities:

	Valuation Technique	Unobservable Inputs	Range	Average
	($ in thousands)
As of December 31, 2022
Contingent consideration payable	Discounted cash flows	Present value factor	0.99		0.99
		April 2022-March 2023 variable fee	$3,556 - $5,658	$4,607
		Percentage of electronic trading volume	86.0% - 96.6%	91.3%
As of December 31, 2021
Contingent consideration payable	Discounted cash flows	Present value factor	0.95 - 1		0.98
		Customer retention rate	84.0%	84.0%
		April 2021-March 2022 variable fee	$2,703 - $3,086	$2,895
		Percentage of electronic trading volume	86.0% - 96.6%	91.3%

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

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

	Carrying Value		Fair Value		Level 1		Level 2		Level 3		Total
	(In thousands)
As of December 31, 2022
Financial assets not measured at fair value:
Cash and cash equivalents	$	371,573	$	371,573	$	371,573	$	—	$	—	$	371,573
Cash segregated under federal regulations		50,947		50,947		50,947		—		—		50,947
Accounts receivable, net of allowance		78,450		78,450		—		78,450		—		78,450
Receivables from broker-dealers, clearing organizations and customers		476,335		476,335		88,923		387,412		—		476,335
Total	$	977,305	$	977,305	$	511,443	$	465,862	$	—	$	977,305
Financial liabilities not measured at fair value:
Payables to broker-dealers, clearing organizations and customers	$	303,993	$	303,993	$	—	$	303,993	$	—	$	303,993
As of December 31, 2021
Financial assets not measured at fair value:
Cash and cash equivalents	$	506,735	$	506,735	$	506,735	$	—	$	—	$	506,735
Cash segregated under federal regulations		50,159		50,159		50,159		—		—		50,159
Accounts receivable, net of allowance		63,881		63,881		—		63,881		—		63,881
Receivables from broker-dealers, clearing organizations and customers		408,346		408,346		68,565		339,781		—		408,346
Total	$	1,029,121	$	1,029,121	$	625,459	$	403,662	$	—	$	1,029,121
Financial liabilities not measured at fair value:
Payables to broker-dealers, clearing organizations and customers	$	229,325	$	229,325	$	—	$	229,325	$	—	$	229,325

Summary of Foreign Currency Forward Contracts

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

	As of December 31,
	2022		2021
	(In thousands)
Notional value	$	62,160	$	—
Fair value of notional		60,472		—
Fair value of the liability	$	1,688	$	—

Summary of Company's Investments

The following table summarizes the Company’s investments:

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
	(In thousands)
As of December 31, 2022
Trading securities
U.S. Treasuries	$	74,943	$	—	$	(534	)	$	74,409
Mutual funds held in rabbi trust		11,474		—		(2,091	)		9,383
Total investments	$	86,417	$	—	$	(2,625	)	$	83,792
As of December 31, 2021
Trading securities
U.S. Treasuries	$	24,994	$	—	$	(111	)	$	24,883
Mutual funds held in rabbi trust		9,941		1,254		—			11,195
Total investments	$	34,935	$	1,254	$	(111	)	$	36,078

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:

	As of December 31,
	2022		2021
	(In thousands)
Less than one year	$	34,001	$	11,195
Due in 1 - 5 years		49,791		24,883
Total	$	83,792	$	36,078