v3.25.4
Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Amount      
U.S federal statutory tax rate $ (171) $ (157) $ (167)
Federal research and development credits (74) (57) (42)
Nontaxable or nondeductible items      
Stock-based compensation (30) (15) 14
Other 7 6 6
Change in unrecognized tax benefits 15 11 8
Change in valuation allowance 253 212 181
Income tax expense $ 0 $ 0 $ 0
Percent      
U.S federal statutory tax rate (as a percent) 21.00% 21.00% 21.00%
Federal research and development credits (as a percent) 9.10% 7.60% 5.30%
Nontaxable or nondeductible items      
Stock-based compensation (as a percent) 3.70% 2.00% (1.80%)
Other (as a percent) (0.90%) (0.80%) (0.80%)
Change in unrecognized tax benefits (as a percent) (1.80%) (1.50%) (1.00%)
Change in federal valuation allowance (as a percent) (31.10%) (28.30%) (22.70%)
Effective tax rate (as a percent) 0.00% 0.00% 0.00%