Fair Value Measurements and Available for Sale Investments (Tables)

9 Months Ended

Sep. 30, 2024

Schedule of Assets and Liabilities that Require Fair Value Measurements on a Recurring Basis

The following table summarizes our assets and liabilities that require fair value measurements on a recurring basis and their respective input levels based on the fair value hierarchy:


	Fair Value Measurements at End of Period Using:
(in thousands)	Fair Value		Quoted Market Prices for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
At September 30, 2024
Money market funds(1)	$	181,132	$	181,132	$	—	$	—
Mutual funds(1)	6,592		6,592		—		—
U.S. Treasury securities(2)	244,051		244,051		—		—

Agency securities(2)	5,015		—		5,015		—
Commercial and corporate obligations(2)	17,384		—		17,384		—

At December 31, 2023
Money market funds(1)	$	27,789	$	27,789	$	—	$	—
Mutual funds(1)	6,286		6,286		—		—
U.S. Treasury securities(2)	325,714		325,714		—		—
Certificates of deposit(2)	244		—		244		—
Agency securities(2)	20,253		—		20,253		—
Commercial and corporate obligations(2)	35,754		—		35,754		—

(1) Included in cash and cash equivalents in the accompanying consolidated balance sheets.

(2) Included in short-term or long-term investments in the accompanying consolidated balance sheets depending on the respective maturity date.

Schedule of Available-for-sale Investments

The aggregate market value, cost basis, and gross unrealized gains and losses of available-for-sale investments by security type, classified in short-term and long-term investments as of September 30, 2024 are as follows:


(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Fair Value
Agency securities(1)	$	5,018	$	—	$	(3)	$	5,015


Commercial and corporate obligations(2)	17,357		28		(1)		17,384
U.S. Treasury securities(3)	243,109		948		(6)		244,051
Total available for sale investments	$	265,484	$	976	$	(10)	$	266,450

(1) Of our outstanding agency securities, $5.0 million have maturity dates of less than one year and $0.0 million have maturity dates between one to two years as of September 30, 2024.

(2) Of our outstanding commercial and corporate obligations, $17.4 million have maturity dates of less than one year and $0.0 million have a maturity date of between one to two years as of September 30, 2024.

(3) Of our outstanding U.S. Treasury securities, $216.1 million have maturity dates of less than one year and $27.9 million have a maturity date of between one to two years as of September 30, 2024.

The aggregate market value, cost basis, and gross unrealized gains and losses of available for sale investments by security type, classified in short-term and long-term investments as of December 31, 2023 are as follows:


(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Fair Value
Agency securities(1)	$	20,322	$	—	$	(69)	$	20,253
Certificates of deposit(2)	246		—		(2)		244
Commercial and corporate obligations(3)	35,760		77		(83)		35,754
U.S. Treasury securities(4)	326,227		122		(635)		325,714
Total available for sale investments	$	382,555	$	199	$	(789)	$	381,965

(1) Of our outstanding agency securities, $20.3 million have maturity dates of less than one year and $0.0 million have a maturity date of between one to two years as of December 31, 2023.

(2) Of our outstanding certificates of deposit, $0.2 million have a maturity date of less than one year and $0.0 million have a maturity date of between one to two years as of December 31, 2023.

(3) Of our outstanding commercial and corporate obligations, $25.8 million have maturity dates of less than one year and $10.0 million have a maturity date of between one to two years as of December 31, 2023.

(4) Of our outstanding U.S. Treasury securities, $308.6 million have maturity dates of less than one year and $17.1 million have a maturity date of between one to two years as of December 31, 2023.

Schedule of Unrealized Loss and Fair Values in a Loss Position

The following tables present gross unrealized losses and fair values for those investments that were in an unrealized loss position as of September 30, 2024 and December 31, 2023, aggregated by investment category and the length of time that individual securities have been in a continuous loss position:


	September 30, 2024
	Less than 12 Months				12 Months or Greater				Total
(in thousands)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Agency securities	$	5,015	$	(3)	$	—	$	—	$	5,015	$	(3)
Commercial and corporate obligations	—		—		2,333		(1)		2,333		(1)

U.S. Treasury Securities	—		—		15,077		(6)		15,077		(6)
Total	$	5,015	$	(3)	$	17,410	$	(7)	$	22,425	$	(10)


	December 31, 2023
	Less than 12 Months				12 Months or Greater				Total
(in thousands)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Agency securities	$	2,530	$	(1)	$	17,723	$	(68)	$	20,253	$	(69)
Certificates of Deposit	—		—		244		(2)		244		(2)
Commercial and corporate obligations	5,160		(9)		15,200		(74)		20,360		(83)
U.S. Treasury Securities	98,840		(110)		99,000		(525)		197,840		(635)
Total	$	106,530	$	(120)	$	132,167	$	(669)	$	238,697	$	(789)