Fair Value Measurements

3 Months Ended

Mar. 31, 2025

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

Assets Measured at Fair Value on a Recurring Basis

The following table presents our financial assets measured at fair value on a recurring basis by level within the fair value hierarchy for the periods indicated (in thousands):

		March 31, 2025
	Valuation	Amortized		Unrealized		Unrealized			Fair
	Hierarchy	Cost		Gains		Losses			Value
Assets:
Money market funds	Level 1	$	9,301	$	—	$	—		$	9,301
Commercial paper	Level 2		101,313		—		(28	)		101,285
U.S. government bonds	Level 2		178,916		347		(15	)		179,248
Agency bonds	Level 2		52,517		68		(2	)		52,583
Corporate debt securities	Level 2		8,331		12		(3	)		8,340
U.S. Treasury securities	Level 2		45,551		2		(2	)		45,551
Agency discount securities	Level 2		5,784		—		—			5,784
Total cash equivalents and marketable securities		$	401,713	$	429	$	(50	)	$	402,092
Classified as:
Cash equivalents									$	78,708
Marketable securities										323,384
Total cash equivalents and marketable securities									$	402,092

		December 31, 2024
	Valuation	Amortized		Unrealized		Unrealized			Fair
	Hierarchy	Cost		Gains		Losses			Value
Assets:
Money market funds	Level 1	$	22,645	$	—	$	—		$	22,645
Commercial paper	Level 2		51,982		14		(5	)		51,991
U.S. government bonds	Level 2		169,860		439		(29	)		170,270
Agency bonds	Level 2		63,753		111		(5	)		63,859
Corporate debt securities	Level 2		6,154		15		(3	)		6,166
U.S. Treasury securities	Level 2		44,499		10		—			44,509
Agency discount securities	Level 2		18,940		2		—			18,942
Total cash equivalents and marketable securities		$	377,833	$	591	$	(42	)	$	378,382
Classified as:
Cash equivalents									$	64,487
Marketable securities										313,895
Total cash equivalents and marketable securities									$	378,382

The valuation techniques used to measure the fair values of our Level 2 financial instruments, which generally have counterparties with high credit ratings, are based on quoted market prices when available. If quoted market prices are not available, the fair value for the security is estimated under the market or income approach using pricing models with market observable inputs.

The following table summarizes the estimated fair value of investments in marketable securities by effective contractual maturity dates as of March 31, 2025 (in thousands):

Within one year	$	369,008
After one year through two years		33,084
Total cash equivalents and marketable securities	$	402,092

As of March 31, 2025, marketable securities in an unrealized loss position include primarily fixed-rate debt securities of varying maturities, which are sensitive to changes in the yield curve and other market conditions. All of the fixed-rate debt securities in a loss position are investment-grade debt securities. We have the intent and ability to hold such securities until recovery of the unrealized losses. Based on our evaluation, the unrealized losses as of March 31, 2025 were insignificant and did not reflect increased credit risks within specific securities holdings. No allowance for credit losses was recorded as of March 31, 2025 and December 31, 2024.

Liabilities Measured at Fair Value on a Recurring Basis

Warrant Liability

As of March 31, 2025, our only financial liability measured at fair value on a recurring basis relates to warrants to purchase up to 311,996 shares of our common stock issued in connection with the Term Loan Facility (see Note 6). The number of warrants that become exercisable is contingent on subsequent loan advances drawn by us under the Term Loan Facility. As such, the warrants are not considered to be indexed to our own stock and were accounted for as a liability. We recorded the fair value of the warrants upon issuance using a probability-weighted scenario analysis with a Black-Scholes option-pricing model. We are required to revalue the warrants at each reporting date with any changes in fair value recorded on the consolidated statements of operations and comprehensive loss until the exercise contingencies are resolved. The valuation of the warrants is considered under Level 3 of the fair value hierarchy, taking into account the likelihood of the warrants becoming exercisable in addition to assumptions used in the Black-Scholes option-pricing model.

The reconciliation of our warrant liability measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows (in thousands):

	Warrant Liability
Balance outstanding as of December 31, 2024	$	516
Change in fair value		(221	)
Balance outstanding as of March 31, 2025	$	295

The warrants had a fair value of $0.3 million as of March 31, 2025, based on a Black-Scholes valuation with the following assumptions: risk-free interest rate of 4.2%, no dividends, expected volatility of 87.8% and expected term of 9.5 years.