Net Loss per Share

6 Months Ended

Jun. 30, 2015

Note 7. Net Loss Per Share

Net loss attributable to common stockholders per share is computed by dividing the net loss allocable to common stockholders by the weighted-average number of shares of common stock or common stock equivalents outstanding. Outstanding stock options, warrants and preferred stock have not been included in the calculation of diluted net loss attributable to common stockholders per share because to do so would be anti-dilutive. Accordingly, the numerator and the denominator used in computing both basic and diluted net loss per share for each period are the same. The following table provides a reconciliation of the numerator and denominator used in computing basic and diluted net loss per share:

	Three Months Ended June 30,						Six Months Ended June 30,
	2015			2014			2015			2014
Numerator:
Net loss	$	(6,452,342	)	$	(3,684,826	)	$	(10,540,477	)	$	(6,512,416	)
Accretion of stock issuance costs		(10,969	)		(186,206	)		(35,046	)		(208,687	)
Accretion of discount on Series E warrants		(40,146	)		(85,717	)		(127,616	)		(137,094	)
Series E and D, preferred stock dividends		(367,350	)		(828,125	)		(1,165,932	)		(1,568,762	)
Net loss attributable to common stockholders	$	(6,870,807	)	$	(4,784,874	)	$	(11,869,071	)	$	(8,426,959	)
Denominator:
Weighted-average common shares outstanding -basic and diluted		3,973,055			96,440			2,163,295			96,426

The following outstanding options, warrants and preferred stock were excluded from the computation of diluted net loss per share for the periods presented because their effect would have been anti-dilutive:

	Six Months Ended June 30,
	2015		2014
Options to purchase common stock		610,090		553,622
Convertible preferred stock (as converted)		—		2,353,163
Convertible preferred stock warrants (as converted)		—		27,534
Common stock warrant		170,587		931