6. Common Shares

Warrants

Outstanding warrants are summarized in the following table:


		Weighted		Weighted
		average		average
	Warrants	exercise price		remaining life
	outstanding	per share		(yrs.)	Intrinsic value
As of December 31, 2017	6,514,625	$	1.92	1.6	$	—
As of December 31, 2018	6,514,625	$	1.92	0.6	$	—
As of June 30, 2019	6,514,625	$	1.92	0.1	$	—

These warrants expire in August 2019.

Stock-Based Compensation

Under the Company’s stock option plan (the “Plan”), we may grant options to purchase common shares in the capital of the Company (“Common Shares”) to our directors, officers, employees and consultants. The maximum number of Common Shares that may be reserved for issuance under the Plan, together with all other stock-based compensation arrangements, which include restricted share units (“RSUs”) currently outstanding under the Company’s long term equity incentive plan (“LTIP”) and deferred share units (“DSUs”) issuable pursuant to the Company’s deferred share unit plan (“DSU Plan”), is a variable number equal to 10% of the issued and outstanding Common Shares on a non-diluted basis at any one time. In 2018, the Company issued phantom units to be settled in cash. Options, RSUs, DSUs, and phantom units are granted from time to time at the discretion of the Board of Directors of the Company (the “Board”), with vesting periods and other terms as determined by the Board.

Stock-based compensation expense for the three and six months ended June 30, 2019 and 2018 is as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018		2019		2018
Stock options	$	81	$	54	$	131	$	200
Restricted stock units		126		192		127		384
Deferred share units		209		—		209		—
	$	416	$	246	$	467	$	584

Phantom units	$	22	$	—	$	44	$	—

As of June 30, 2019, unrecognized compensation expense for stock options, RSUs, and phantom units was $132, $569, and $134, respectively, which is expected to be recognized over weighted average periods of 1.0, 1.5, and 1.0 years, respectively.

Stock Options

A summary of options under the Plan as of June 30, 2019 is set forth in the following table:


				Weighted average
		Weighted average		remaining	Aggregate
	Number of	exercise price		contractual term	intrinsic
	options	per option		(years)	value
Outstanding - December 31, 2017	1,144,500		0.42	1.15	$	346
Granted	1,142,000		0.71
Exercised	(218,600)		0.39			36
Cancelled/Forfeited	(748,751)		0.36			—
Outstanding - December 31, 2018	1,319,149	$	0.71	3.84	$	1
Granted	350,000		0.73
Exercised	(127,000)		0.52			29
Cancelled/Forfeited	(149)		0.52			—
Outstanding - June 30, 2019	1,542,000	$	0.73	3.98	$	67

Exercisable - June 30, 2019	877,330	$	0.75	3.86	$	28

A summary of unvested stock options as of June 30, 2019 is set forth in the following table:


				Weighted
		Weighted		average
		average		remaining
		grant-date		amortization
	Number of	fair value		period
	options	per option		(years)
Unvested - December 31, 2017	246,250		0.22	0.99
Granted	1,142,000		0.45
Cancelled/Forfeited	(246,250)		0.22
Vested	(382,331)		0.45
Unvested - December 31, 2018	759,669	$	0.45	1.14
Granted	350,000		0.30
Vested	(444,999)		0.41
Unvested - June 30, 2019	664,670	$	0.40	0.99

The fair value of stock options granted to employees, directors and consultants was estimated at the grant date using the Black-Scholes option pricing model using the following weighted average assumptions:



	2019		2018
Expected volatility	61.1	%	77.1	%
Risk-free interest rate	2.0	%	2.6	%
Expected life (years)	2.8		5.0
Dividend yield	0	%	0	%
Forfeiture assumption	0	%	0	%

Restricted Stock Units

The following table summarizes the RSUs outstanding under the LTIP as of June 30, 2019:


		Weighted average
	Number	grant-date fair
	of RSUs	value per RSU
Unvested - December 31, 2017	1,567,907	$	0.85
Granted	319,000		0.75
Cancelled/forfeited	(246,683)		0.90
Vested, net of shares withheld	(637,554)		0.88
Unvested - December 31, 2018	1,002,670	$	0.78
Granted	1,349,000		0.47
Cancelled/forfeited	(198,821)		0.76
Vested, net of shares withheld	(142,380)		0.75
Unvested - June 30, 2019	2,010,469	$	0.58

A portion of the RSU awards vest on a fixed future date provided the recipient continues to be affiliated with Vista on that date. Other RSU awards vest subject to certain performance and market criteria, including the accomplishment of certain corporate objectives and the Company’s share price performance. The minimum vesting period for RSUs is one year.

During the six months ended June 30, 2019, the Company withheld Common Shares with an equivalent value to meet the employee withholding tax obligations which resulted from RSUs that vested in the period. Common Shares withheld are considered cancelled/forfeited.

Deferred Share Units

In May 2019, the Company’s shareholders approved the DSU Plan. The DSU Plan provides for granting of DSUs to non-employee directors. DSUs vest immediately, however the Company will issue one Common Share for each DSU only after the non-employee director has ceased to be a director of the Company. Additionally, in May 2019, the Company’s shareholders approved an amendment to the LTIP such that non-employee directors are excluded from future grants under the LTIP. At the time the DSU Plan was approved, the Board granted 366,000 DSUs and the Company recognized $209 in DSU expense.

The following table summarizes the DSUs outstanding as of June 30, 2019:



		Weighted average
	Number of	grant-date fair
	DSUs	value per DSU
Outstanding - December 31, 2018	—	—
Granted	366,000	0.57
Outstanding - June 30, 2019	366,000	0.57

Phantom Units

In 2018, the Company granted a total of 265,000 phantom units to certain employees. The value of each unit is equal to the Company’s share price on the vesting date and is payable in cash. The phantom units vest on fixed future dates provided the recipient continues to be affiliated with Vista on those dates. The Company will account for these units as awards classified as liabilities with $67 included in current liabilities as of June 30, 2019. The Company recognized $22 and $44 of compensation expense for these phantom units in the three and six months ended June 30, 2019 respectively.

A summary of unvested phantom units as of June 30, 2019 is set forth in the following table:


		Weighted average
		remaining
	Number of	vesting term
	phantom units	(years)
Unvested - December 31, 2017	—
Granted	265,000
Unvested - December 31, 2018	265,000	1.50
Granted	—
Unvested - June 30, 2019	265,000	1.00