Share Capital (Tables)

9 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

The following table presents stock option activity for the period:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Outstanding, beginning of period		5,771,051			4,595,432			4,758,997			3,534,236
Granted		236,200			194,400			1,730,650			1,440,050
Exercised⁽¹⁾		(41,974	)		(375	)		(386,708	)		(153,417	)
Forfeited, cancelled or expired		(45,843	)		(3,363	)		(183,505	)		(34,775	)
Outstanding, end of period		5,919,434			4,786,094			5,919,434			4,786,094
Exercisable, end of period		3,068,278			2,324,090			3,068,278			2,324,090

(1)

During the nine months ended September 30, 2021, 61,072 stock options were exercised for the same number of common shares in exchange for cash (nine months ended September 30, 2020 – 10,715). In the same period, the Company issued 196,206 common shares (nine months ended September 30, 2020 – 85,816) for the cashless exercise of 325,636 stock options (nine months ended September 30, 2020 – 142,702).

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 September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Average risk-free interest rate		1.00	%		0.40	%		1.16	%		0.72	%
Expected volatility		68	%		68	%		68	%		68	%
Average expected term (in years)		6.77			6.64			6.69			6.79
Expected dividend yield		0	%		0	%		0	%		0	%
Weighted average fair value of stock options granted	$	10.74		$	7.03		$	12.41		$	7.46