Share Capital (Tables)

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

The following table presents stock option activity for the period:

	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Outstanding, beginning of period		5,742,608			4,527,992			4,758,997			3,534,236
Granted		382,500			127,300			1,494,450			1,245,650
Exercised⁽¹⁾		(222,331	)		(54,716	)		(344,734	)		(153,042	)
Forfeited, cancelled or expired		(131,726	)		(5,144	)		(137,662	)		(31,412	)
Outstanding, end of period		5,771,051			4,595,432			5,771,051			4,595,432
Exercisable, end of period		2,842,948			2,114,647			2,842,948			2,114,647

(1)

During the six months ended June 30, 2021, 58,179 (six months ended June 30, 2020 – 10,715) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 179,129 (six months ended June 30, 2020 – 85,660) common shares for the cashless exercise of 286,555 (six months ended June 30, 2020 – 142,327) stock options.

Fair Value Assumptions for Stock Options

The fair value of each stock option granted is estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Average risk-free interest rate		1.27	%		0.48	%		1.18	%		0.77	%
Expected volatility		69	%		68	%		68	%		68	%
Average expected term (in years)		7.09			6.86			6.67			6.75
Expected dividend yield		0	%		0	%		0	%		0	%
Weighted average fair value of stock options granted	$	12.14		$	8.27		$	12.67		$	7.50