Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

The provision for income taxes is based on net loss before income taxes as follows:



	DECEMBER 31,
(in thousands)	2019			2018			2017
Net loss before income taxes:
United States	$	(153,620	)	$	(203,230	)	$	(133,113	)
Non-U.S.	(46,051		)	(29,336		)	(13,750		)
Net loss before income taxes	$	(199,671	)	$	(232,566	)	$	(146,863	)

The components of the provision for income taxes are as follows:
	DECEMBER 31,
(in thousands, except percentages)	2019			2018			2017
Provision for income taxes:
Current:
United States	$	(90	)	$	3		$	(24	)
Non-U.S.	—			—			—
Total	$	(90	)	$	3		$	(24	)
Deferred:
United States	$	—		$	—		$	(1,734	)
Non-U.S.	—			—			—
Total	—			—			(1,734		)
Provision for income taxes	$	(90	)	$	3		$	(1,758	)
Effective tax rate	0.05		%	—		%	1.20		%

Significant components of the Company’s net deferred income tax assets as of December 31, 2019 and 2018 consist of the following:



	DECEMBER 31,
(in thousands)	2019			2018
Net deferred tax assets:
Net operating loss carryforwards	$	142,991		$	112,375
Stock-based compensation	22,785			17,734
U.S. tax credit carryforwards	10,980			5,996
Envisia asset acquisition	5,476			5,888
Basis difference in intangibles	7,625			—
Convertible Notes	(22,822		)	—
Other assets	5,154			2,857
Other liabilities	(1,867		)	(1,535		)
Valuation allowance	(170,322		)	(143,315		)
Total net deferred income taxes	$	—		$	—

A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 31, 2019, 2018 and 2017 is as follows:



	DECEMBER 31,
	2019		2018		2017
U.S. federal tax rate	21.00	%	21.00	%	35.00	%
Impact of federal tax legislation	—	%	—	%	25.82	%
State income taxes, net of federal benefit	4.97	%	4.56	%	7.71	%
Non-taxable foreign loss	(4.44	)%	0.09	%	(0.51	)%
Stock-based compensation	(1.47	)%	1.97	%	(0.02	)%
Other	0.98	%	(1.13	)%	(2.19	)%
Change in valuation allowance	(20.99	)%	(26.49	)%	(64.61	)%
Effective tax rate	0.05	%	—	%	1.20	%