Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Summary of income tax expense (benefit)

Income (loss) before income taxes consisted entirely of income (loss) from domestic operations of $(4.9) million, $6.0 million and $133.7 million for the calendar year ended December 31, 2019, 2020 and 2021, respectively. Income tax expense (benefit) included in the statements of operations and comprehensive income (loss) consisted of the following:

	Year Ended December 31,
	2019		2020		2021
Current:
Federal	$	—	$	—	$	—
State	74		371		229
Total current tax expense	74		371		229
Deferred:
Federal	—		—		(1,435)
State	—		—		(506)
Total deferred tax expense	—		—		(1,941)
Total provision (benefit) for income taxes	$	74	$	371	$	(1,712)

Schedule of effective tax reconciled to federal statutory income tax rate

Income tax expense differed from the amount computed by applying the federal statutory income tax rate of 21% to pretax income as a result of the following:

	Year Ended December 31,
	2019		2020		2021
Federal tax at statutory rate	$	(1,039)	$	1,271	$	28,084
State income taxes, net of federal tax benefit	74		369		(248)
Fair value adjustment on warrants	(253)		2,371		—
Stock-based compensation	411		(1,476)		(236,726)
Research and development credit	(372)		(1,231)		(19,103)
PPP loan forgiveness (CARES Act)	—		(1,110)		1,110
Change in valuation allowance	(844)		273		222,230
Tax return to tax provision adjustment	1,028		(216)		(34)
Section 162(m) limitation	—		—		2,653
Noncontrolling interests	956		85		—
Other	113		35		322
Provision (benefit) for income taxes	$	74	$	371	$	(1,712)

Deferred tax assets and liabilities

The tax effects of temporary differences that gave rise to significant portions of the Company’s deferred tax assets and liabilities related to the following:

	December 31,
	2020		2021
Deferred tax assets:
Net operating loss carryforwards	$	14,716	$	297,851
Operating lease liabilities	5,680		29,870
Research and development credits	3,146		29,046
Convertible debt transactions	—		15,184
Stock-based compensation	1,734		9,895
Investment in partnerships	896		1,020
Accruals and reserves	525		6,908
Servicing rights	416		—
Amortization	127		111
Other	75		573
Total deferred tax assets	27,315		390,458
Less: valuation allowance	(21,241)		(351,542)
Deferred tax assets – net of valuation allowance	6,074		38,916
Deferred tax liabilities:
Right of use asset	5,351		28,606
Depreciation	723		2,123
Servicing rights			2,859
Intangible assets	—		5,911
Total deferred tax liabilities	6,074		39,499
Net deferred tax liabilities	$	—	$	(583)

Unrecognized tax benefits roll forward

A reconciliation of the beginning and ending balances of gross unrecognized tax benefits is as follows:

	Year Ended December 31,
	2019		2020		2021
Balance at beginning of year	$	697	$	1,031	$	1,820
Additions for tax positions of prior years	69		—		461
Tax positions related to the current year	265		789		11,623
Balance at end of year	$	1,031	$	1,820	$	13,904