5. FAIR VALUE MEASUREMENTS
The following tables present information about our financial assets and liabilities that are measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques we utilized to determine such fair value: 
(In thousands)As of December 31,
2025
Quoted Prices in Active Markets
(Level 1)
Significant Observable Inputs
(Level 2)
Significant Unobservable Inputs
(Level 3)
Financial assets
Cash equivalents:
Money market funds$140,445 $140,445 $— $— 
U.S. treasury securities18,952 — 18,952 — 
U.S. government-sponsored enterprise securities2,690 — 2,690 — 
Commercial paper1,995 — 1,995 — 
Marketable debt securities:
U.S. treasury securities653,341 — 653,341 — 
Corporate notes333,241 — 333,241 — 
U.S. government-sponsored enterprise securities252,634 — 252,634 — 
Commercial paper7,017 — 7,017 — 
Municipal securities5,001 — 5,001 — 
Restricted cash (money market funds)917 917 — — 
Total financial assets$1,416,233 $141,362 $1,274,871 $— 
(In thousands)As of December 31,
2024
Quoted Prices in Active Markets
(Level 1)
Significant Observable Inputs
(Level 2)
Significant Unobservable Inputs
(Level 3)
Financial assets
Cash equivalents:
Money market funds$190,779 $190,779 $— $— 
U.S. treasury securities36,428 — 36,428 — 
Commercial paper22,709 — 22,709 — 
U.S. government-sponsored enterprise securities9,952 — 9,952 — 
Marketable debt securities:
U.S. treasury securities921,627 — 921,627 — 
U.S. government-sponsored enterprise securities396,143 — 396,143 — 
Corporate notes361,739 — 361,739 — 
Commercial paper35,408 — 35,408 — 
Municipal securities
5,003 — 5,003 — 
Marketable equity securities8,156 8,156 — — 
Restricted cash (money market funds)910 910 — — 
Total financial assets$1,988,854 $199,845 $1,789,009 $— 
Financial liabilities
Development derivative liability$486,919 $— $— $486,919 
For the years ended December 31, 2025 and 2024, there were no transfers between Level 1 and Level 2 financial assets or liabilities. The carrying amounts reflected on our consolidated balance sheets for cash, accounts receivable, net, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term maturities.

Historical Timeline

Fiscal YearFiled
2025Feb 12, 2026Showing above
2024Feb 13, 2025
2023Feb 15, 2024
2022Feb 23, 2023
2021Feb 10, 2022
2020Feb 11, 2021
2019Feb 13, 2020
2018Feb 14, 2019
2017Feb 15, 2018
2016Feb 15, 2017
2015Feb 12, 2016

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.