9. Net Loss Per Share

Basic and diluted net loss per share attributable to common stockholders was calculated as follows:

 

		Year Ended December 31,
		2016				2015				2014
		(in thousands, except per share data)
Basic and diluted net loss per share attributable to common stockholders:
Numerator:
Net loss		$	(57,878	)		$	(74,286	)		$	(36,478	)
Accretion of redeemable convertible preferred stock to redemption value			—				—				(92	)
Net loss attributable to common stockholders		$	(57,878	)		$	(74,286	)		$	(36,570	)
Denominator:
Weighted average common shares outstanding, basic and diluted			27,297,934				26,756,079				12,189,155
Net loss per share attributable to common stockholders, basic and diluted		$	(2.12	)		$	(2.78	)		$	(3.00	)

The Company excluded the following common stock equivalents, outstanding as of December 31, 2016, 2015 and 2014, from the computation of diluted net loss per share attributable to common stockholders for the years ended December 31, 2016, 2015 and 2014 because they had an anti-dilutive impact due to the net loss attributable to common stockholders incurred for the periods:

 

		As of December 31,
		2016				2015				2014
Options to purchase common stock			3,115,003				2,555,110				2,008,574