Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2022

Stock-based compensation

Share-based Payment Arrangement, Option, Activity

	Number of	Weighted Avg
	Options	Exercise Price
Balance at December 31, 2021	50,717,724	$	0.45
Stock options granted	21,000,000		0.32
Stock options exercised	—		—
Stock options forfeited	1,250,000		0.67
Vested stock options expired	8,960,000		0.22
Balance at June 30, 2022	61,507,724	$	0.43
Vested at June 30, 2022	15,596,349	$	0.36

Summary of issued and outstanding stock options

				Number of	Weighted avg
		Number of options	Number of	unvested	remaining life
		issued	vested options	options	outstanding
Grant date	Exercise price	and outstanding	outstanding	outstanding	(years)
March 14, 2020	0.19	1,283,557	949,682	333,875	2.71
July 9, 2020	0.18	175,000	87,500	87,500	3.03
August 25, 2020	0.13	20,000	—	20,000	3.16
October 1, 2020	0.11	266,667	116,667	150,000	3.26
October 20, 2020	0.09	20,000	10,000	10,000	3.31
December 31, 2020	0.23	16,442,500	8,807,500	7,635,000	3.51
February 26, 2021	1.87	500,000	300,000	200,000	3.66
March 1, 2021	2.06	200,000	100,000	100,000	3.67
March 8, 2021	1.88	200,000	100,000	100,000	3.69
March 15, 2021	2.49	200,000	100,000	100,000	3.71
May 12, 2021	0.78	3,450,000	900,000	2,550,000	3.87
May 14, 2021	0.75	3,200,000	850,000	2,350,000	3.87
August 11, 2021	0.57	1,100,000	175,000	925,000	4.12
August 18, 2021	0.50	200,000	—	200,000	4.14
August 23, 2021	0.50	100,000	—	100,000	4.15
September 13, 2021	0.57	800,000	—	800,000	4.21
October 1, 2021	0.58	12,650,000	—	12,650,000	4.26
January 3, 2022	0.36	100,000	—	100,000	4.52
January 4, 2022	0.35	200,000	—	200,000	4.52
January 14, 2022	0.35	200,000	—	200,000	4.55
January 16, 2022	0.35	325,000	—	325,000	4.55
January 18, 2022	0.35	100,000	—	100,000	4.56
February 14, 2022	0.30	400,000	—	400,000	4.63
February 21, 2022	0.37	200,000	—	200,000	4.65
February 25, 2022	0.35	12,400,000	—	12,400,000	4.66
March 30, 2022	0.35	200,000	—	200,000	4.75
April 1, 2022	0.34	200,000	—	200,000	4.76
April 6, 2022	0.32	100,000	—	100,000	4.77
April 7, 2022	0.31	200,000	—	200,000	4.77
April 11, 2022	0.31	75,000	—	75,000	4.78
May 2, 2022	0.25	300,000	—	300,000	4.84
May 9, 2022	0.21	700,000	—	700,000	4.86
May 11, 2022	0.20	400,000	—	400,000	4.87
May 16, 2022	0.23	100,000	—	100,000	4.88
May 31, 2022	0.24	500,000	—	500,000	4.92
June 1, 2022	0.25	500,000	—	500,000	4.92
June 6, 2022	0.26	200,000	—	200,000	4.94
June 13, 2022	0.24	200,000	—	200,000	4.96
June 17, 2022	0.24	3,100,000	3,100,000	—	4.97
Balance at June 30, 2022		61,507,724	15,596,349	45,911,375

Summary of option fair value assumptions

	February 26,			March 1,			March 8,
	2021			2021			2021
Volatility		117	%		117	%		117	%
Risk-free interest rate		0.95	%		0.92	%		1.07	%
Expected life (in years)		10			10			10
Dividend yield		0	%		0	%		0	%
Common share price	$	1.87		$	2.06		$	1.88
Strike price	$	1.87		$	2.06		$	1.88
Forfeiture rate		0	%		0	%		0	%

	May 12,			August 11,			August 23,
	2021			2021			2021
Volatility		118	%		116	%		116	%
Risk-free interest rate		1.11	%		0.96	%		0.92	%
Expected life (in years)		6.21-6.22			6.18-6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.78		$	0.56		$	0.50
Strike price	$	0.78		$	0.57		$	0.50
Forfeiture rate		0	%		0	%		0	%

	September 27,			October 1,
	2021			2021
Volatility		116	%		116	%
Risk-free interest rate		1.14	%		1.10	%
Expected life (in years)		6.25			6.25
Dividend yield		0	%		0	%
Common share price	$	0.54		$	0.57
Strike price	$	0.54		$	0.58
Forfeiture rate		0	%		0	%

	January 3,			January 4,			January 14,
	2022			2022			2022
Volatility		114	%		114	%		114	%
Risk-free interest rate		1.50	%		1.47	%		1.64	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.36		$	0.35		$	0.35
Strike price	$	0.36		$	0.35		$	0.35
Forfeiture rate		0	%		0	%		0	%
	January 16,			January 18,			February 14,
	2022			2022			2022
Volatility		114	%		114	%		113	%
Risk-free interest rate		1.73	%		1.74	%		1.94	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.35		$	0.35		$	0.29
Strike price	$	0.35		$	0.35		$	0.30
Forfeiture rate		0	%		0	%		0	%
	February 21,			February 25,			March 30,
	2022			2022			2022
Volatility		113	%		113	%		114	%
Risk-free interest rate		1.89	%		1.91	%		2.43	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.37		$	0.35		$	0.35
Strike price	$	0.37		$	0.35		$	0.35
Forfeiture rate		0	%		0	%		0	%

	April 1,			April 6,			April 7,
	2022			2022			2022
Volatility		114	%		114	%		114	%
Risk-free interest rate		2.53	%		2.70	%		2.72	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.33		$	0.32		$	0.31
Strike price	$	0.34		$	0.32		$	0.31
Forfeiture rate		0	%		0	%		0	%
	April 11,			May 2,			May 9,
	2022			2022			2022
Volatility		114	%		113	%		113	%
Risk-free interest rate		2.82	%		3.03	%		3.00	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.30		$	0.25		$	0.21
Strike price	$	0.31		$	0.25		$	0.21
Forfeiture rate		0	%		0	%		0	%
	May 11,			May 16,			May 31,
	2022			2022			2022
Volatility		113	%		113	%		113	%
Risk-free interest rate		2.92	%		2.86	%		2.84	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.20		$	0.22		$	0.23
Strike price	$	0.20		$	0.23		$	0.24
Forfeiture rate		0	%		0	%		0	%

	June 1,			June 6,			June 13,
	2022			2022			2022
Volatility		113	%		113	%		112	%
Risk-free interest rate		2.96	%		3.05	%		3.55	%
Expected life (in years)		6.25			6.25			6.25
Dividend yield		0	%		0	%		0	%
Common share price	$	0.25		$	0.26		$	0.24
Strike price	$	0.25		$	0.26		$	0.24
Forfeiture rate		0	%		0	%		0	%
	June 17,			June 17,			June 17,
	2022			2022			2022
Volatility		112	%		112	%		112	%
Risk-free interest rate		3.02	%		3.02	%		3.35	%
Expected life (in years)		1.37			1.64			4.27
Dividend yield		0	%		0	%		0	%
Common share price	$	0.24		$	0.24		$	0.24
Strike price	$	0.24		$	0.24		$	0.24
Forfeiture rate		0	%		0	%		0	%