11. Net Loss Per Share Attributable to Common Stockholders

The following table presents the calculation of basic and diluted net income (loss) per share of common stock for the periods indicated:


	Three Months Ended
	March 31,
	2019		2018
		(unaudited)
Net loss attributable to common shareholders (basic and diluted)	$	(8,303,871)	$	(6,691,637)
Shares used to compute net loss per common share, basic and diluted		34,524,145		8,631,142
Net loss per share attributable to common shareholders, basic and diluted	$	(0.24)	$	(0.75)

Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common shares and common share equivalents outstanding for the period. Common stock equivalents are only included when their effect is dilutive. The Company's potentially dilutive securities which include stock options, convertible preferred stock and common stock warrants have been excluded from the computation of diluted net loss per share as they would be anti-dilutive. For all periods presented, there is no difference in the number of shares used to compute basic and diluted shares outstanding due to the Company's net loss position.

The following outstanding common stock equivalents have been excluded from diluted net loss per common share for the three months ended March 31, 2019 and 2018 because their inclusion would be anti-dilutive.


	March 31,	March 31,
	2019	2018
	(unaudited)
Options issued and outstanding	2,843,754	1,043,070
Inducement options issued and outstanding	208,865	—
Warrants to purchase common stock	5,027,495	321,335
Restricted stock units	392,904	392,923
Convertible preferred stock	33,149,556	3,314,956
Convertible debt	759,396	759,396
Total	42,381,970	5,831,680