Income Taxes (Tables)

12 Months Ended

Dec. 31, 2024

Loss before income taxes included the following (in millions):

The provision for income taxes included the following (in millions):

The reconciliation between the federal statutory income tax rate and our effective tax rate was as follows:


	Year Ended December 31,
	2024		2023		2022
Federal statutory income tax rate	21.0	%	21.0	%	21.0	%
State taxes, net of federal benefit	—	%	(0.7)	%	(0.1)	%
Equity investment	4.1	%	0.4	%	0.9	%
Research and development credits	5.4	%	5.2	%	3.1	%
Change in valuation allowance	(28.1)	%	(26.3)	%	(24.5)	%
Stock based compensation	(1.9)	%	(2.1)	%	0.1	%
Non-deductible expenses and other	(0.7)	%	0.5	%	(0.6)	%
Provision for income taxes	(0.2)	%	(2.0)	%	(0.1)	%

Significant components of our deferred tax assets and liabilities were as follows (in millions):


	Year Ended December 31,
	2024		2023
Deferred tax assets:
Federal and state net operating loss carryforwards	$	5	$	1
Research and development credits carryforwards	42		26
Stock-based compensation	27		21
Depreciation and amortization	3		3
Deferred revenue	45		66
Lease liability	24		26
Capitalized research and development costs	178		109
Other	6		1
Total deferred tax assets	330		253
Deferred tax liabilities:
Right-of-use assets	(14)		(20)
Total deferred tax liabilities	(14)		(20)
Less valuation allowance	(316)		(233)
Net deferred tax assets (liabilities)	$	—	$	—

The following table summarizes the activity related to our unrecognized tax benefits (in millions):


	Year Ended December 31,
	2024		2023
Beginning balance	$	13	$	8
Additions for tax positions taken in prior year	1		2
Additions for tax positions taken in current year	5		3
Ending balance	$	19	$	13