8. Net Loss Per Share

Basic and diluted net loss per share was calculated as follows for the three and six months ended June 30, 2017 and 2016:

	Three months ended June 30,						Six months ended June 30,
	2017			2016			2017			2016
Basic net loss per share:
Numerator:
Net loss (in thousands)	$	(70,202	)	$	(34,747	)	$	(126,979	)	$	(65,290	)
Denominator:
Weighted average common stock outstanding—basic		37,361,129			32,062,298			37,315,393			31,835,194
Dilutive effect of shares of common stock equivalents resulting from common stock options and restricted stock units		—			—			—			—
Weighted average common stock outstanding—diluted		37,361,129			32,062,298			37,315,393			31,835,194
Net loss per share—basic and diluted	$	(1.88	)	$	(1.08	)	$	(3.40	)	$	(2.05	)

The following common stock equivalents outstanding as of June 30, 2017 and 2016 were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive:

	Three months ended June 30,				Six months ended June 30,
	2017		2016		2017		2016
Stock options		5,313,821		3,445,537		5,313,821		3,445,537
Restricted stock units		30,400		—		30,400		—
Employee stock purchase plan		8,697		7,192		8,697		7,192
Restricted stock awards		—		11,236		—		11,236
		5,352,918		3,463,965		5,352,918		3,463,965