12. Net Loss Per Share

Basic and diluted net loss per share for the years ended December 31, 2018 and 2017 was calculated as follows:


	Year Ended		Year Ended
	December 31,		December 31,
	2018		2017
Numerator:
Net loss	$	(23,138)	$	(29,727)
Accretion of preferred stock to redemption value		—		(244)
Net loss attributable to common stockholders for basic loss per share	$	(23,138)	$	(29,971)
Less change in fair value of warrant liability		7,284		473
Net loss attributable to common stockholders for diluted loss per share	$	(30,422)	$	(30,444)
Denominator:
Weighted average number of common shares outstanding-basic		14,144,287		9,161,844
Assumed conversion of dilutive securities:
Private Placement Warrants		268,408		26,743
Denominator for diluted loss per share-adjusted weighted average shares		14,412,695		9,188,587
Net loss per share attributable to common stockholders-basic	$	(1.64)	$	(3.27)
Net loss per share attributable to common stockholders-diluted	$	(2.11)	$	(3.31)

The Company’s potentially dilutive securities include stock options and warrants. These securities were excluded from the computations of diluted net loss per share for the years ended December 31, 2018 and 2017, as the effect would be to reduce the net loss per share. During the years ended December 31, 2018 and 2017, the outstanding warrants issued with the Private Placement is reflected in the diluted net loss per share computation by applying the treasury stock method. The following table includes the potential common shares, presented based on amounts outstanding at each period end, that were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:


	Year Ended December 31,
	2018	2017
Options to purchase common stock	2,761,912	2,257,621
Warrants assumed from Macrocure	54,516	54,516
	2,816,428	2,312,137