(2) Earnings (Loss) per Share

Basic earnings (loss) per share is calculated by dividing net income (loss) available to common shareholders by the weighted average number of common shares outstanding during the period. Diluted earnings (loss) per share is based on the weighted average number of common shares outstanding plus, where applicable, the additional potential common shares that would have been outstanding related to dilutive options and unvested restricted stock units to the extent such shares are dilutive.

The following table sets forth the computation of basic and diluted earnings (loss) per share of common stock for the three and nine months ended September 30, 2019 and 2018:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Basic loss per share attributable to common stock:
Numerator
Net loss	$	(3,060,200)	$	(2,459,072)	$	(9,715,269)	$	(8,434,543)

Denominator
Weighted avg. common shares outstanding		24,911,908		21,266,639		24,301,045		21,265,247

Basic loss per share attributable to common stock	$	(0.12)	$	(0.12)	$	(0.40)	$	(0.40)

Diluted loss per share attributable to common stock:
Numerator
Net loss	$	(3,060,200)	$	(2,459,072)	$	(9,715,269)	$	(8,434,543)
Denominator
Weighted avg. common shares outstanding		24,911,908		21,266,639		24,301,045		21,265,247

Diluted loss per share attributable to common stock	$	(0.12)	$	(0.12)	$	(0.40)	$	(0.40)

The computation of diluted loss per share for the nine months ended September 30, 2019 and 2018 does not include the following stock options and unvested restricted stock units to purchase shares in the computation of diluted loss per share because these instruments were antidilutive:


	September 30,
	2019	2018
Stock options	2,310,485	2,208,228
Unvested restricted stock units	678,687	164,623