Investments

6 Months Ended

Jun. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Investments

4. Investments

The following tables summarize the fair value and amortized cost of the Company’s available-for-sale securities by major security type including gross unrealized gains and losses and credit losses as of June 30, 2024 and December 31, 2023:

	June 30, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	84,623	$	—	$	(115	)	$	—	$	84,508
U.S. corporate bonds		205,746		6		(358	)		—		205,394
International corporate bonds		109,641		15		(166	)		—		109,490
U.S. commercial paper		67,152		3		(1	)		—		67,154
International commercial paper		45,109		1		(1	)		—		45,109
U.S. certificates of deposit		2,203		—		—			—		2,203
U.S. municipal securities		33,109		—		(75	)		—		33,034
	$	547,583	$	25	$	(716	)	$	—	$	546,892

	December 31, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	167,165	$	107	$	(347	)	$	—	$	166,925
U.S. corporate bonds		210,491		191		(484	)		—		210,198
International corporate bonds		97,698		99		(122	)		—		97,675
U.S. commercial paper		23,360		11		(1	)		—		23,370
International commercial paper		46,935		3		(38	)		—		46,900
U.S. certificates of deposit		8,830		—		—			—		8,830
U.S. municipal securities		128,527		26		(259	)		—		128,294
	$	683,006	$	437	$	(1,251	)	$	—	$	682,192

As of June 30, 2024 and December 31, 2023, the Company had $3.8 million and $4.2 million, respectively, of accrued interest receivable relating to the Company’s available-for-sale securities which is included within prepaid expenses and other current assets in the accompanying condensed consolidated balance sheets.

No accrued interest receivable was written off during the three and six months ended June 30, 2024 and 2023. Realized gains or losses were immaterial for the three and six months ended June 30, 2024 and 2023.

The following tables summarize the fair value and the unrealized losses of the Company’s marketable securities that have been in a loss position for either less than twelve months or greater than twelve months as of June 30, 2024 and December 31, 2023:

	June 30, 2024
	Less than 12 months					Greater than 12 months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(in thousands)
U.S. government securities	$	46,179	$	(44	)	$	33,425	$	(71	)	$	79,604	$	(115	)
U.S. corporate bonds		165,291		(246	)		30,021		(112	)		195,312		(358	)
International corporate bonds		79,172		(109	)		19,985		(57	)		99,157		(166	)
U.S. commercial paper		12,887		(1	)		—		—			12,887		(1	)
International commercial paper		3,908		(1	)		—		—			3,908		(1	)
U.S. municipal securities		14,818		(31	)		18,216		(44	)		33,034		(75	)
	$	322,255	$	(432	)	$	101,647	$	(284	)	$	423,902	$	(716	)

	December 31, 2023
	Less than 12 months					Greater than 12 months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(in thousands)
U.S. government securities	$	52,521	$	(96	)	$	41,911	$	(251	)	$	94,432	$	(347	)
U.S. corporate bonds		111,901		(246	)		43,851		(238	)		155,752		(484	)
International corporate bonds		43,708		(87	)		6,014		(35	)		49,722		(122	)
U.S. commercial paper		7,848		(1	)		—		—			7,848		(1	)
International commercial paper		37,300		(38	)		—		—			37,300		(38	)
U.S. municipal securities		90,095		(143	)		31,345		(116	)		121,440		(259	)
	$	343,373	$	(611	)	$	123,121	$	(640	)	$	466,494	$	(1,251	)

As of June 30, 2024 and December 31, 2023, the unrealized losses on the Company’s investments in U.S. government securities, U.S. corporate bonds, international corporate bonds, and U.S. municipal securities were caused by interest rate increases. The Company purchased those investments at a premium relative to their face amount. The current credit ratings are all within the guidelines of the investment policy of the Company and the Company does not expect the issuers to settle any security at a price less than the amortized cost basis of the investment. As of June 30, 2024, the Company does not intend to sell those investments and it is not probable that the Company will be required to sell the investments before recovery of their amortized cost basis.

As of June 30, 2024, all marketable securities held by the Company had remaining contractual maturities of one year or less, except for U.S. corporate bonds, international corporate bonds and U.S. municipal securities with a fair value of $43.4 million and maturities of one to two years.

As of December 31, 2023, all marketable securities held by the Company had remaining contractual maturities of one year or less, except for U.S. government securities, U.S. corporate bonds, international corporate bonds and U.S. municipal securities with a fair value of $110.3 million and maturities of one to two years.

All marketable securities, including those with remaining contractual maturities of more than one year, are classified as current assets on the balance sheet because they are considered to be “available-for-sale” and the Company can convert them into cash to fund current operations.

There have been no impairments of the Company’s assets measured and carried at fair value during the six months ended June 30, 2024 and the year ended December 31, 2023.