5. ADDITIONAL PAID IN CAPITAL

6 Months Ended

Jun. 30, 2017

Additional Paid in Capital [Abstract]

ADDITIONAL PAID IN CAPITAL

Stock-based compensation

As of June 30, 2017, we have 3,744,900 options outstanding and exercisable that were issued under the 10% Rolling Stock Option Plan (“RSOP”).

The fair value of each employee stock option award is estimated at the grant date using a Black-Scholes option pricing model and the price of our common shares on the date of grant. The significant assumptions used to estimate the fair value of stock options awarded during the six months ended June 30, 2017, using a Black-Scholes option pricing model are as follows:

Risk-free interest rate	0.8	%
Expected volatility	133.37	%
Expected dividend yield	nil
Expected term in years	5.0
Estimated forfeiture rate	nil

The compensation expense recognized in our consolidated financial statements for the three months ended June 30, 2017 and 2016 for stock option awards was $11 and $23, respectively, and $31 and $56 for the six months ended June 30, 2017 and 2016, respectively. As of June 30, 2017, all outstanding stock options were vested and all related compensation expense was recognized.

The following table summarizes our stock option activity for each of the six months ended June 30, 2017 and 2016:

	2017					2016
	Number of Stock Options			Weighted Average Exercise Price		Number of Stock Options			Weighted Average Exercise Price
Outstanding, beginning of period		3,694,900		$	0.94		4,578,700		$	3.99
Granted		150,000			0.15		—			—
Cancelled/Expired		(100,000	)		0.04		(1,291,300	)		7.89
Outstanding, end of period		3,744,900		$	0.93		3,287,400		$	2.70
Exercisable, end of period		3,744,900		$	0.93		3,023,200		$	2.89
Weighted-average fair value per share of options granted during period	$	0.15					n/a