Net Loss Per Share

Basic net loss per share is computed by dividing the net loss for the year by the weighted average number of common shares outstanding during the year. Diluted net loss per share is calculated in accordance with the treasury stock method and reflects the potential dilution that would occur if securities or other contracts to issue common stock were exercised or converted to common stock. The calculation of diluted net loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the options, warrants or other securities and the presumed exercise of such securities are dilutive to net loss per share for the period, an adjustment to net loss used in the calculation is required to remove the change in fair value of such securities from the numerator for the period. Likewise, an adjustment to the denominator is required to reflect the related dilutive shares, if any, under the treasury stock method.

The following tables reconcile the components of the numerator and denominator included in the calculations of diluted net loss per share:



	Three Months Ended June 30,
	2018			2017
Numerator
Net loss	$	(6,639,125	)	$	(9,479,116	)
Adjustment for decrease in fair value of warrant liability	(259,971		)	—
Numerator for use in diluted net loss per share	$	(6,899,096	)	$	(9,479,116	)

Denominator
Weighted average number of common shares outstanding	91,153,776			75,409,702
Effect of dilutive potential common shares	87,884			—
Denominator for use in diluted net loss per share	91,241,660			75,409,702

Net loss per share, diluted	$	(0.08	)	$	(0.13	)



	Six Months Ended June 30,
	2018			2017
Numerator
Net loss	$	(38,989,953	)	$	(32,565,023	)
Adjustment for decrease in fair value of warrant liability	(132,130		)	—
Numerator for use in diluted net loss per share	$	(39,122,083	)	$	(32,565,023	)

Denominator
Weighted average number of common shares outstanding	90,804,722			74,783,791
Effect of dilutive potential common shares	86,070			—
Denominator for use in diluted net loss per share	90,890,792			74,783,791

Net loss per share, diluted	$	(0.43	)	$	(0.44	)

The following table summarizes potential shares of common stock that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect for the three and six months ended June 30, 2018 and 2017:




Common Stock Equivalents	2018	2017
Options to purchase common stock	9,245,981	7,888,763
Warrants to purchase common stock	—	284,091
Restricted stock units	1,760,710	1,335,744
Convertible preferred stock	8,456	8,456
Total	11,015,147	9,517,054