Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Effective Income Tax Reconciliation

The differences between the effective income tax rate and the statutory tax rates during the years ended 2020, 2019 and 2018 are as follows (in thousands):


	Year Ended December 31,
	2020			2019			2018
Net loss before tax	$	(357,937)		$	(213,256)		$	(98,418)
Statutory combined U.S. federal and state tax rate	21.00		%	21.00		%	21.00		%
Statutory federal and state taxes	(75,167)			(44,784)			(20,668)
State income taxes, net of federal benefit	(13,490)			—			—
Increase (decrease) in taxes recoverable resulting from:
Effect of change in valuation allowance	110,985			52,719			25,959
Non-deductible share-based compensation	2,724			1,810			884
Tax deductions for share-based compensation	(17,991)			(6,917)			(2,924)
Tax credits	(15,672)			(8,621)			(5,130)
Uncertain tax positions	3,857			2,143			1,283
Return to provision and other true-ups	25			(60)			375
Non-deductible officers' compensation	4,697			3,527			179
Other differences	32			183			42
Income tax benefit	$	—		$	—		$	—

Schedule of Deferred Tax

The following table summarizes the significant components of the Company's deferred tax assets (in thousands):


	December 31,
	2020		2019
Deferred tax assets:
Tangible and intangible depreciable assets	$	32,180	$	6,978
Stock compensation	19,183		12,321
Provisions	2,510		934
Other, net	—		35
Lease liability	8,800		137
Net operating loss carry forwards	182,536		116,345
Capital loss carryforward	114		178
Canada scientific research and experimental development expenditures	5,471		5,471
U.S. research and development tax credits	28,834		17,080
Total gross deferred tax assets	279,628		159,479
Less valuation allowance	(270,368)		(159,357)
Net deferred tax assets	$	9,260	$	122

Deferred tax liabilities:
Right-of-use asset	$	(8,377)	$	(122)
Non-current investment	(883)		—

Net deferred income taxes	$	—	$	—

Schedule of Expiration of NOLs

The NOLs expire as follows (in thousands):


	US				Canada
	Federal		State		Federal		Provincial
Expires in:
2030	$	—	$	—	$	4,830	$	4,907
2031	—		—		7,059		7,066
2032	—		—		13,308		12,433
2033	2,225		2,232		18,623		19,385
2034	7,276		22,162		32,401		31,809
2035	53,359		52,950		1,084		1,084
2036	23,379		—		777		777
2037	65,509		—		697		697
2038	—		3,817		—		—
2039	—		—		242		242
2040	—		193,163		273		273
Does not expire	551,134		—		—		—
	$	702,882	$	274,324	$	79,294	$	78,673

Schedule of Unrecognized Tax Positions

A reconciliation of the beginning and ending amounts of unrecognized tax positions are as follows (in thousands):


	Federal						Provincial/State
	December 31,						December 31,
	2020		2019		2018		2020		2019		2018
Unrecognized tax positions, beginning of year	$	4,268	$	2,617	$	1,693	$	8,648	$	8,010	$	7,556

Gross increase — current period tax positions	3,126		1,651		924		1,004		638		454
Gross decrease — prior period tax positions	—		—		—		—		—		—
Gross increase — prior period tax positions	—		—		—		—		—		—
Expiration of statute of limitations	—		—		—		—		—		—
Unrecognized tax positions, end of year	$	7,394	$	4,268	$	2,617	$	9,652	$	8,648	$	8,010