Net Loss Per Share

Basic and diluted net loss per share is calculated as follows (in thousands, except share and per share amounts):



	Year Ended December 31,
	2017			2016			2015
Numerator:
Net loss	$	(254,237	)	$	(182,804	)	$	(101,526	)
Loss attributable to common stockholders—basic	(254,237		)	(182,804		)	(101,526		)
Effect of dilutive convertible preferred stock	—			—			—
Loss attributable to common stockholders—diluted	$	(254,237	)	$	(182,804	)	$	(101,526	)
Denominator:
Weighted-average number of common shares used in loss per share— basic and diluted	43,804,660			43,067,952			39,643,099
Loss per share—basic and diluted	$	(5.80	)	$	(4.24	)	$	(2.56	)

The following potentially dilutive securities, prior to the use of the treasury stock method, have been excluded from the computation of diluted weighted-average shares outstanding, as they would be anti-dilutive. For the years ended December 31, 2017, 2016, and 2015 all of the Company's classes of convertible preferred stock, options to purchase common stock, warrants and performance units outstanding were assumed to be anti-dilutive as earnings attributable to common stockholders was in a loss position.



	Year Ended December 31
	2017	2016	2015
Convertible preferred stock	—	—	—
Options to purchase common stock	5,647,895	6,373,542	4,408,369
Warrants	605,415	605,415	631,587
Restricted Stock Units	146,451	56,250	—