6. Common Shares

Warrants

Warrant activity is 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 September 30, 2018	6,514,625	$	1.92	0.9	$	—

Stock-Based Compensation

Under the Company’s stock option plan (the “Plan”), we may grant options to purchase common shares of the Company (“Common Shares”) to our directors, officers, employees and consultants. The maximum number of our Common Shares that may be reserved for issuance under the Plan, together with RSUs currently outstanding under the LTIP, is a variable number equal to 10% of the issued and outstanding Common Shares on a non-diluted basis at any one time. Options under the Plan are granted from time to time at the discretion of the Board, with vesting periods and other terms as determined by the Board.

Stock-based compensation expense for the three and nine months ended September 30, 2018 and 2017 is as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Stock options	$	107	$	8	$	307	$	32
Restricted stock units		164		245		548		648
	$	271	$	253	$	855	$	680

Phantom units (Discussed below)		11		—		11		—

As of September 30, 2018, stock options, RSUs, and phantom units had unrecognized compensation expense of $223, $324, and $122 respectively, which is expected to be recognized over a weighted average period of 1.2, 0.9, and 1.8 years, respectively.

Stock Options

A summary of options under the Plan as of September 30, 2018 is set forth in the following table:


		Weighted average		Weighted average	Aggregate
	Number of	exercise price		remaining	intrinsic
	options	per option		contractual term	value
Outstanding - December 31, 2017	1,144,500	$	0.42	1.15	$	346
Granted	1,142,000		0.71
Exercised	(40,000)		0.40
Outstanding - September 30, 2018	2,246,500	$	0.57	2.51	$	130

Exercisable - September 30, 2018	1,240,581	$	0.52	1.71	$	94

A summary of our unvested stock options as of September 30, 2018 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
Vested	(382,331)		0.45
Unvested - September 30, 2018	1,005,919	$	0.39	1.24

No stock options were granted for the nine months ended September 30, 2017. The fair value of stock options granted during the nine months ended September 30, 2018 to employees, directors and consultants was estimated at the grant date using the Black-Scholes option pricing model using the following assumptions:



	2018
Expected volatility	76.2	%
Risk-free interest rate	2.7	%
Expected life (years)	5
Dividend yield	—
Forfeiture assumption	—	%

Option Amendment

In July 2018, the Company amended certain 2013 stock option agreements, expiring December 30, 2018 subject to the potential for a temporary extension under the terms of the Plan, for seven executives and directors (the “Option Amendment”). The amendment provides each grantee the opportunity to receive a cash buyout of certain vested, unexercised 2013 options in lieu of exercising the option to purchase shares. This cash buyout is based on the intrinsic value of each option at the time of the buyout. As a result of this modification, the Company will account for these options as awards classified as liabilities with $72 included in current liabilities. The options were previously accounted for as awards classified as equity. The Company recognized no additional compensation expense for these options in the nine months ended September 30, 2018.

Restricted Stock Units

The following table summarizes the RSUs outstanding under the LTIP as of September 30, 2018:


		Weighted average
	Number	grant-date fair
	of RSUs	value per RSU
Unvested - December 31, 2017	1,567,907	$	0.85
Cancelled/forfeited	(246,683)		0.90
Vested, net of shares withheld	(637,554)		0.88
Granted	319,000		0.75
Unvested - September 30, 2018	1,002,670	$	0.78

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 nine months ended September 30, 2018, the Company withheld shares with an equivalent value to meet the employee withholding tax obligations which resulted from RSUs that vested in the period. Shares withheld are considered cancelled/forfeited.

New RSUs will not be granted under the LTIP until the allocation of such awards is duly approved by the shareholders of the Company.

Phantom Units


		Weighted average
	Number of	remaining
	phantom units	contractual term
Unvested - December 31, 2017	—
Granted	265,000
Unvested - September 30, 2018	265,000	1.75

The Company granted a total of 265,000 phantom units to certain employees during the nine months ended September 30, 2018. 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 $11 included in current liabilities as of September 30, 2018. The Company recognized $11 of compensation expense for these options in the nine months ended September 30, 2018.