Fair Value Measurements
Assets and liabilities measured at fair value are classified into the following categories:
Level 1: Quoted market prices in active markets for identical assets or liabilities.
Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.
Level 3: Unobservable inputs reflecting the reporting entity’s own assumptions or external inputs from inactive markets.
We classify our cash equivalents and marketable securities within Level 1 or Level 2 because we use quoted market prices or alternative pricing sources and models utilizing observable market-based inputs to determine their fair value.
The following tables set forth our financial assets that are measured at fair value on a recurring basis, excluding publicly traded equity securities, as of December 31, 2025 and 2024:
December 31, 2025
Fair Value HierarchyCost or
Amortized Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Total Estimated
Fair Value
(in thousands)
Cash$399,573 $— $— $399,573 
Cash equivalents:
Money market fundsLevel 1630,862 — — 630,862 
Total cash and cash equivalents1,030,435 — — 1,030,435 
Marketable debt securities:
U.S. government securitiesLevel 11,796,271 6,479 (5)1,802,745 
Corporate debt securitiesLevel 297,701 161 (6)97,856 
Total marketable debt securities1,893,972 6,640 (11)1,900,601 
Total$2,924,407 $6,640 $(11)$2,931,036 
December 31, 2024
Fair Value HierarchyCost or
Amortized Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Total Estimated
Fair Value
(in thousands)
Cash$348,251 $— $— $348,251 
Cash equivalents:
Money market fundsLevel 1694,323 — (30)694,293 
U.S. government securitiesLevel 13,991 — (1)3,990 
Total cash and cash equivalents1,046,565 — (31)1,046,534 
Marketable debt securities:
U.S. government securitiesLevel 12,186,192 4,984 (3,292)2,187,884 
Corporate debt securitiesLevel 2129,217 229 (5)129,441 
Total marketable debt securities2,315,409 5,213 (3,297)2,317,325 
Total$3,361,974 $5,213 $(3,328)$3,363,859 
Gross unrealized losses on marketable debt securities were not material as of December 31, 2025 and 2024. As of December 31, 2025 and 2024, we considered any decreases in fair value on our marketable debt securities to be driven by factors other than credit risk, including market risk. As of December 31, 2025, $0.9 billion of our total $1.9 billion in marketable debt securities have contractual maturities between one and five years. All other marketable debt securities have contractual maturities less than one year.
We hold investments in publicly traded companies with an aggregate carrying value of $9.5 million and $12.4 million as of December 31, 2025 and 2024, respectively, recorded as marketable securities. We classify these publicly traded equity securities within Level 1 because we use quoted market prices to determine their fair value. Gains
and losses recognized during the periods presented, which are included within other income (expense), net on our consolidated statements of operations, were as follows:
Year Ended December 31,
202520242023
(in thousands)
Gains (losses) recognized on publicly traded equity securities sold during the period, net$— $— $11,046 
Unrealized gains (losses) on publicly traded equity securities still held at the reporting date, net(5,636)(1,185)(17,731)
Gains (losses) on publicly traded equity securities, net$(5,636)$(1,185)$(6,685)
We carry the Notes at face value less any unamortized debt issuance costs and discounts, plus unamortized premiums on our consolidated balance sheets and present the fair value for disclosure purposes only. As of December 31, 2025, the fair value of the 2026 Notes, the 2027 Notes, the 2028 Notes, the 2030 Notes, the 2033 Notes and the 2034 Notes was $45.8 million, $99.1 million, $467.9 million, $655.4 million, $1,553.8 million, and $566.2 million respectively. As of December 31, 2024, the fair value of the 2025 Notes, the 2026 Notes, the 2027 Notes, the 2028 Notes and the 2030 Notes was $35.5 million, $242.7 million, $998.5 million, $1,226.6 million, and $635.6 million, respectively. The estimated fair value of the Notes, which are classified as Level 2 financial instruments, was determined based on the estimated or actual bid prices of the Notes in an over-the-counter market on the last business day of the period.
Schedule of Cash, Cash Equivalents, and Restricted Cash
The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in our consolidated balance sheets to the total of the amounts in the consolidated statements of cash flows.
As of December 31,
202520242023
(in thousands)
Cash and cash equivalents$1,030,435 $1,046,534 $1,780,400 
Restricted cash, included in other assets962 3,700 2,062 
Total cash, cash equivalents, and restricted cash$1,031,397 $1,050,234 $1,782,462 

Historical Timeline

Fiscal YearFiled
2025Feb 5, 2026Showing above
2024Feb 5, 2025
2023Feb 7, 2024
2022Feb 1, 2023
2021Feb 4, 2022
2020Feb 5, 2021
2019Feb 5, 2020
2018Feb 6, 2019
2017Feb 22, 2018

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.