Fair Value Measurements and Available for Sale Investments
Fair Value Measurements
The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:
Level 1: Observable inputs such as quoted prices in active markets;
Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and
Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.
The Company classifies its cash equivalents and available-for-sale investments within Level 1 or Level 2. The fair value of the Company’s investment grade corporate debt securities and commercial paper classified as Level 2 is determined using proprietary valuation models and analytical tools, which utilize market pricing or prices for similar instruments that are both objective and publicly available, such as matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, and offers.
Assets and Liabilities Measured at Fair Value on a Recurring Basis
The following table presents the hierarchy for assets measured at fair value on a recurring basis as of December 31, 2025 and 2024 (in thousands):
Fair Value Measurements at End of Period Using:
Total
Fair Value
Quoted Market
Prices for
Identical Assets
(Level 1)
Significant
Other Observable
Inputs
(Level 2)
Significant
Unobservable
Inputs
(Level 3)
As of December 31, 2025
Money market funds$22,228 $22,228 $— $— 
U.S. Treasury and agency securities8,090 8,090 — — 
Commercial paper73,592 — 73,592 — 
Corporate debt securities27,377 — 27,377 — 
As of December 31, 2024
Money market funds$25,264 $25,264 $— $— 
U.S. Treasury and agency securities56,900 56,900 — — 
Commercial paper188,653 — 188,653 — 
Corporate debt securities19,963 — 19,963 — 
The Company did not reclassify any investments between levels in the fair value hierarchy during the periods presented.
Fair Value of Other Financial Instruments
As of December 31, 2025 and 2024, the carrying amounts of the Company’s financial instruments, which include cash, prepaid and other current assets, interest receivable, accrued research and development expenses, accounts payable and accrued expenses and other current liabilities, approximate fair values because of their short-term maturities.
As of December 31, 2025 and 2024, the interest receivable was $0.3 million and $0.2 million, respectively. Interest receivable is recorded as a component of prepaid expenses and other current assets on the consolidated balance sheets.
As of December 31, 2025 and 2024 the fair value of the Company's 2027 Notes was $138.3 million and $110.0 million, respectively. The fair value was determined on the basis of market prices observable for similar instruments and is considered Level 2 in the fair value hierarchy (see Note 5).
Available for Sale Investments
The Company invests its excess cash in U.S. Treasury and agency securities, corporate debt securities, and commercial paper, which are classified as available-for-sale investments. These investments are carried at fair value and are included in the tables below. The Company evaluates securities with unrealized losses to determine whether such losses, if any, are due to credit-related factors. Realized gains and losses are calculated using the specific identification method and recorded in other income, net in the Company's consolidated statements of operations and comprehensive loss. The Company has classified these investments as available-for-sale, as the sale of such investments may be required prior to maturity to implement management strategies, and therefore has classified all investment securities as current assets.
The aggregate market value, cost basis, and gross unrealized gains and losses of available-for-sale investments by security type, classified in marketable securities as of December 31, 2025 and 2024 are as follows (in thousands except securities amounts):
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Total
Fair Value
As of December 31, 2025
U.S Treasury and agency securities$8,088 $$— $8,090 
Corporate debt securities27,359 18 — 27,377 
Commercial paper73,544 49 (1)73,592 
Total marketable securities$108,991 $69 $(1)$109,059 
Number of securities with unrealized losses
As of December 31, 2024
   U.S. Treasury and agency securities$56,875 $25 $— $56,900 
   Corporate debt securities19,950 $13 — 19,963 
Commercial paper188,537 142 (26)188,653 
Total marketable securities$265,362 $180 $(26)$265,516 
Number of securities with unrealized losses
As of December 31, 2025 and 2024, the Company classified $22.2 million and $25.3 million, respectively, of assets with original maturities of three months or less as cash and cash equivalents.
At each reporting date, the Company performs an evaluation of impairment to determine if any unrealized losses are due to credit-related factors. The Company records an allowance for credit losses when unrealized losses are due to credit-related factors. Factors considered when evaluating available-for-sale investments for impairment include the severity of the impairment, changes in underlying credit ratings, the financial condition of the issuer, the probability that the scheduled cash payments will continue to be made and the Company’s intent and ability to hold the investment until recovery of the amortized cost basis. The Company does not intend to sell these debt securities that are in an unrealized loss position, and it is not more likely than not that the Company will be required to sell these debt securities before recovery of their amortized cost bases, which may be at maturity. Based on the credit quality of the debt securities, and the Company’s estimates of future cash flows to be collected from those securities, the Company believes the unrealized losses are not credit losses. As of December 31, 2025 and 2024, there were no material declines in the market value of the Company's available-for-sale investments due to credit-related factors.
Contractual maturities of available-for-sale debt securities, as of December 31, 2025, were as follows (in thousands):
Estimated
Fair Value
Less than one year$109,059 
Greater than one year— 
Total$109,059 
The Company has the ability, if necessary, to liquidate any of its cash equivalents and marketable securities to meet its liquidity needs in the next 12 months.

Historical Timeline

Fiscal YearFiled
2025Mar 17, 2026Showing above
2024Mar 13, 2025
2023Mar 5, 2024
2021Mar 3, 2022
2020Feb 26, 2021
2019Mar 24, 2020

About Fair Value Disclosures

Fair value disclosures classify all assets and liabilities measured at fair value into a three-level hierarchy: Level 1 (quoted market prices), Level 2 (observable inputs like yield curves), and Level 3 (unobservable inputs requiring management estimates). The proportion of Level 3 assets directly reflects how much of the balance sheet depends on internal models rather than market evidence.

Key signals: a growing Level 3 balance relative to total fair-value assets increases valuation uncertainty and earnings volatility risk. Watch for transfers between levels — assets moving from Level 2 to Level 3 often signal deteriorating market liquidity. Unrealized gains and losses on Level 3 positions flow through earnings or other comprehensive income, so large swings deserve scrutiny. For financial institutions, examine the sensitivity disclosures that show how Level 3 valuations change under alternative assumptions. Compare the fair value of debt against its carrying amount to gauge hidden leverage.