3. Earnings per Common Share

Basic earnings per share is computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the three months and nine months ended September 30, 2018 and 2017 .

Diluted earnings per share is computed by dividing net income (loss) attributable to common stockholders, by the sum of (1) the weighted-average number of shares of common stock outstanding during the period, (2) the dilutive effect of the assumed exercise of convertible instruments and (3) the dilutive effect of the exercise of stock options and other stock units to our common stock.

For the three months and nine months ended September 30, 2018, common stock equivalents from convertible instruments, stock options and other stock units have been excluded from the calculation of weighted average diluted shares because all such instruments were anti-dilutive.

The following table sets forth the computation of basic and diluted weighted average common shares.

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2018		2017		2018		2017
Weighted average basic shares		8,934,005		8,598,461		8,819,700		8,478,848
Dilutive effect of preferred stock, warrants, stock options and restricted stock units		2,212,389		-		-		-
Total weighted average diluted shares		11,146,394		8,598,461		8,819,700		8,478,848