Investment Securities

6 Months Ended

Jun. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Investment Securities

5. Investment Securities

The Company’s investment policy defines allowable investment securities and establishes guidelines relating to credit quality, diversification, and maturities of its investments to preserve principal and maintain liquidity. The Company’s investment securities consisted of the following at June 30, 2024 and December 31, 2023 (in thousands):

		As of June 30, 2024
											Estimated
									Allowance		Fair
		Amortized		Unrealized		Unrealized			for Credit		Market
	Maturity	Cost		Gains		Losses			Losses		Value
Certificates of deposits	Within 1 year	$	5,100	$	1	$	(14	)	$	—	$	5,087
U.S. Treasury securities	Within 1 year		145,082		2		(138	)		—		144,946
U.S. Government agency securities	Within 1 year		2,500		—		(5	)		—		2,495
Certificates of deposits	1 year to 2 years		1,658		2		(1	)		—		1,659
U.S. Treasury securities	1 year to 2 years		49,694		16		(65	)		—		49,645
U.S. Government agency securities	1 year to 2 years		11,500		—		(15	)		—		11,485
Total		$	215,534	$	21	$	(238	)	$	—	$	215,317
		As of December 31, 2023
											Estimated
									Allowance		Fair
		Amortized		Unrealized		Unrealized			for Credit		Market
	Maturity	Cost		Gains		Losses			Losses		Value
Certificates of deposits	Within 1 year	$	10,488	$	2	$	(23	)	$	—	$	10,467
U.S. Treasury securities	Within 1 year		162,746		70		(349	)		—		162,467
U.S. Government agency securities	Within 1 year		12,499		—		(29	)		—		12,470
Certificates of deposits	1 year to 2 years		3,862		12		(5	)		—		3,869
U.S. Treasury securities	1 year to 2 years		58,441		412		(16	)		—		58,837
U.S. Government agency securities	1 year to 2 years		12,500		2		(14	)		—		12,488
Total		$	260,536	$	498	$	(436	)	$	—	$	260,598

The Company reviews its investments at each reporting date to identify and evaluate whether a decline in fair value below the amortized cost basis of available-for-sale securities is due to credit-related factors and determines if such unrealized losses are the result of credit losses that require impairment. Factors considered in determining whether an unrealized loss is the result of a credit loss or other factors include the extent to which the fair value is less than the cost basis, any changes to the rating of the security by a rating agency, the financial condition and near-term prospects of the issuer, any historical failure of the issuer to make scheduled interest or principal payments, any adverse legal or regulatory events affecting the issuer or issuer’s industry, any significant deterioration in economic condition and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.

There were 76 and 71 securities in an unrealized loss position at June 30, 2024 and December 31, 2023, respectively. The Company determined that unrealized losses on its available-for-sale investment securities were primarily attributable to changes in interest rates. Each security remained at a high credit quality rating. Further, there had been no adverse conditions noted for any of the issuers and the Company does not intend to sell any of the securities prior to maturity. As such, an allowance for credit losses has not been recognized as of June 30, 2024 or December 31, 2023.

The following tables present available-for-sale investments that were in an unrealized loss position as of June 30, 2024 and December 31, 2023, aggregated by security type and length of time in a continuous unrealized loss position (in thousands):

	As of June 30, 2024
	Less than 12 Months					12 Months or Greater					Total
	Estimated					Estimated					Estimated
	Fair					Fair					Fair
	Market		Unrealized			Market		Unrealized			Market		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Certificates of deposits	$	2,685	$	(10	)	$	1,910	$	(5	)	$	4,595	$	(15	)
U.S. Treasury securities		147,757		(156	)		17,393		(47	)		165,150		(203	)
U.S. Government agency securities		11,485		(15	)		2,495		(5	)		13,980		(20	)
Total	$	161,927	$	(181	)	$	21,798	$	(57	)	$	183,725	$	(238	)
	As of December 31, 2023
	Less than 12 Months					12 Months or Greater					Total
	Estimated					Estimated					Estimated
	Fair					Fair					Fair
	Market		Unrealized			Market		Unrealized			Market		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Certificates of deposits	$	8,514	$	(14	)	$	1,456	$	(14	)	$	9,970	$	(28	)
U.S. Treasury securities		44,346		(102	)		51,979		(263	)		96,325		(365	)
U.S. Government agency securities		12,484		(16	)		7,473		(27	)		19,957		(43	)
Total	$	65,344	$	(132	)	$	60,908	$	(304	)	$	126,252	$	(436	)

As of June 30, 2024, the Company held 28 domestic certificates of deposit with amortized costs below the Federal Deposit Insurance Corporation insured limit. Accrued interest receivable on available-for-sale investment securities, included in prepaid expenses and other current assets on the Company’s balance sheets, was $1.4 million as of both June 30, 2024 and December 31, 2023.