4. SHAREHOLDERS' EQUITY (Tables)

3 Months Ended

Mar. 31, 2020

Equity [Abstract]

Fair value assumptions

	March 31, 2019
Risk-free interest rate		2.24%
Expected volatility		75%
Expected dividend yield		Nil
Expected term in years		2.5
Estimated forfeiture rate		Nil
Estimated exercise price		$0.34
Estimated enterprise value per common share		$0.00

	Three months ended March 31,
	2020		2019
Risk-free interest rate		1.45%		2.49%
Expected volatility		148%		141%
Expected dividend yield		Nil		Nil
Expected term in years		5.0		5.0
Estimated forfeiture rate		Nil		Nil

Stock option activity

	2020				2019
	Number of Stock Options		Weighted Average Exercise Price		Number of Stock Options			Weighted Average Exercise Price
Outstanding, beginning of period		3,450,000	$	0.16		3,385,400		$	0.44
Granted		750,000		0.83		850,000			0.07
Exercised (1)		100,000		0.32		—			—
Cancelled/Expired		—		—		(41,400	)		0.32
Outstanding, end of period		4,100,000	$	0.28		4,194,000		$	0.21
Exercisable, end of period		2,925,000	$	0.17		2,969,000		$	0.24
Weighted-average fair value per share of options granted during period	$	0.75			$	0.07

(1) The 100,000 stock options exercised resulted in 40,186 common shares being issued under the net settlement option pursuant to the terms of the 10% Rolling Stock Option Plan for the three months ended March 31, 2020.