Investments

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Investments

6.Investments

Available-for-sale investments consisted of the following as of December 31, 2023 and 2022 (in thousands):

	December 31, 2023
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Short-term marketable securities
Commercial paper	$	10,630	$	—	$	—		$	10,630
U.S. government treasury and agency securities		264,214		232		(20	)		264,426
Corporate bonds		6,278		3		—			6,281
Total short-term marketable securities	$	281,122	$	235	$	(20	)	$	281,337

	December 31, 2022
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Short-term marketable securities
Commercial paper	$	9,969	$	—	$	—		$	9,969
U.S. government treasury securities		389,898		14		(4,064	)		385,848
Corporate bonds		12,415		—		(66	)		12,349
Total short-term marketable securities	$	412,282	$	14	$	(4,130	)	$	408,166

All the U.S. government treasury and agency securities, corporate bonds and commercial paper designated as short-term marketable securities have an effective maturity date that is equal to or less than one year from the respective consolidated balance sheet date. Those that are designated as long-term marketable securities have an effective maturity date that is more than one year from the respective consolidated balance sheet date.

Accrued interest receivable is excluded from the amortized cost and estimated fair value of our marketable securities. Accrued interest receivable of $1.0 million and $0.8 million was presented separately within the prepaid expenses and other current assets balance on the consolidated balance sheet as of December 31, 2023 and 2022, respectively.

The following table presents the gross unrealized holding losses and fair values for investments in an unrealized loss position, and the length of time individual securities have been in a continuous loss position, as of December 31, 2023 (in thousands):

	Less Than 12 Months					12 Months Or Greater
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
U.S. government treasury and agency securities	$	48,100	$	(20	)	$	—	$	—
Total available-for-sale securities	$	48,100	$	(20	)	$	—	$	—

We periodically review our available-for-sale securities to assess for credit impairment. Some of the factors considered in assessing impairment include the extent to which the fair value is less than the amortized cost basis, adverse conditions related to the security, an industry or geographic area, changes to security ratings or sector credit ratings and other relevant market data.

As of December 31, 2023, we did not intend, nor were we more likely than not to be required, to sell our available-for-sale investments before the recovery of their amortized cost basis, which may be maturity. Based on our assessment, we concluded all impairment as of December 31, 2023 to be due to factors other than credit loss, such as changes in interest rates. A credit allowance was not recognized and the impairment of our available-for-sale securities was recorded in other comprehensive loss.