4. Loss Per Share

The Company calculates net loss per share in accordance with ASC 260, Earnings Per Share. Under the provisions of ASC 260, basic net loss per share is computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding for the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive common stock equivalents then outstanding. Common stock equivalents consist of shares of common stock issuable upon the exercise of stock options and warrants.

The following table sets forth the computation for basic and diluted loss per share:

	Three Months				Nine Months
	Ended September 30,				Ended September 30,
	2013		2014		2013		2014

	(Unaudited)				(Unaudited)

Numerator:
Net loss	$	(2,718,126)	$	(3,643,946)	$	(4,839,585)	$	(10,287,300)
Numerator for basic and diluted earnings per share	$	(2,718,126)	$	(3,643,946)	$	(4,839,585)	$	(10,287,300)
Denominator:
Denominator for basic and diluted earnings per share — weighted-average shares		33,137,368		38,732,896		32,911,836		38,728,454
Basic and diluted loss per share	$	(0.08)	$	(0.09)	$	(0.15)	$	(0.27)

Outstanding stock options to purchase 1,439,876 and 2,799,888 shares of common stock of the Company for the periods ended September 30, 2013 and 2014, respectively, were excluded from the calculation of diluted loss per share as their effect would have been antidilutive. Outstanding warrants to purchase 681,090 shares of common stock of the Company for the period ended September 30, 2014 were excluded from the calculation of diluted loss per share as its effect would have been antidilutive. Also excluded from the calculation were 270,000 and 311,667 unvested shares of restricted common stock for both of the periods ended September 30, 2013 and 2014.