11. Stock-Based Compensation

A summary of the fair value of all awards issued under Vista's stock compensation plans included within Shareholders' Equity is as follows:

	Years Ended December 31,
	2011		2010			2009

Balance, Beginning of Year	$	4,695	$	4,917		$	4,161
Stock options		238		(348	)		756
Restricted stock units		132		126			-
Balance, End of Year	$	5,065	$	4,695		$	4,917

Stock Option Plan

Under our Stock Option Plan (the “Plan”), we may grant options 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 those reserved for issuance under the LTIP (as discussed below), is a variable number equal to 10% of the issued and outstanding Common Shares on a non-diluted basis. Under the Plan, the exercise price of each option shall not be less than the market price of our Common Shares on the date preceding the date of grant, and each option's maximum term is 10 years or such other shorter term as stipulated in a stock option agreement between Vista and the optionee. Options under the Plan are granted from time to time at the discretion of the Board of Directors (“Board of Directors” or “Board”), with vesting periods and other terms as determined by the Board.

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

	Years Ended December 31,
	2011	2010	2009

Expected volatility	83.40%-83.86%	81.86%-82.88%	76.42%-78.80%
Risk-free interest rate	0.88%-1.60%	1.51%-2.88%	1.80%-2.58%
Expected life (years)	5	5	5
Dividend yield	N/A	N/A	N/A

Option pricing models require the input of highly subjective assumptions, including the expected price volatility. Expected price volatility is based on the historical volatility of our Common Shares. Changes in the subjective input assumptions can materially affect the fair value estimate. The expected term of the options granted is derived from the output of the option pricing model and represents the period of time that the options granted are expected to be outstanding. The risk-free rate for the periods within the contractual term of the option is based on the U.S. Treasury yield curve in effect at the date of grant.

A summary of option activity under the Plan as of December 31, 2011 and changes during the year then ended is set forth in the following table:

	Number of shares			Weighted average exercise price per share		Weighted average remaining contractual term		Aggregate intrinsic value
Outstanding - December 31, 2008		2,184,747		$	4.39		3.55	$	-
Granted		860,000
Exercised		(83,195	)
Forfeited		(2,500	)
Cancelled		(7,500	)
Expired		(163,407	)
Outstanding - December 31, 2009		2,788,145		$	3.75		3.43	$	534
Granted		165,000
Exercised		(30,000	)
Cancelled		(325,000	)
Expired		(9,484	)
Outstanding - December 31, 2010		2,588,661		$	3.55		2.90	$	463
Granted		1,246,000
Exercised		(354,984	)
Forfeited/ Cancelled		(85,500	)
Expired		(199,177	)
Outstanding - December 31, 2011		3,195,000		$	3.27		2.73	$	1,039

Exercisable - December 31, 2011		2,597,500		$	3.32		2.32	$	957

The total number of options outstanding at December 31, 2011 is 3,195,000 with exercise prices ranging from approximately $1.77 to $7.45 and remaining lives of 0.58 to 4.88 years. The total number of options outstanding represents 4.47% of issued capital.

Compensation expense with a fair value of $1,496, $382, and $888 was recognized during the years ended December 31, 2011, 2010 and 2009, respectively.

Under the Plan, 1,246,000 stock options, which vest over a period of two years (623,000 in each year), were granted to our employees, directors and consultants during the year ended December 31, 2011. The fair value of the 623,000 options immediately vested has been recorded as a non-cash compensation expense of $571. The weighted average grant-date fair value of the 1,246,000 options granted during the year ended December 31, 2011 was $1.60.

Under the Plan, 165,000 stock options, which vest over a period of two years (82,500 in each year), were granted to our employees and consultants during the year ended December 31, 2010. The 82,500 immediately vested options had a fair value of $112. The weighted average grant-date fair value of the 165,000 options granted during the year ended December 31, 2010 was $1.36.

Under the Plan, 860,000 stock options, which vest over a period of two years (430,000 in each year), were granted to our employees, directors and consultants during the year ended December 31, 2009. The 430,000 immediately vested options had a fair value of $398. The weighted average grant-date fair value of the 860,000 options granted during the year ended December 31, 2009 was $0.93.

During the year ended December 31, 2011, 354,984 options were exercised that had an aggregate intrinsic value of $806. During the year ended December 31, 2010, 30,000 options were exercised that had an aggregate intrinsic value of $18. During the year ended December 31, 2009 83,195 options were exercised. There was no intrinsic value associated with the options exercised during 2009.

A summary of the status of our unvested stock options as of December 31, 2011, and changes during the year then ended, is set forth below:

	Number of shares			Weighted average grant-date fair value per share
Unvested - December 31, 2008		415,000		$	1.32
Granted		430,000			0.92
Vested		(412,500	)		1.32
Forfeited		(2,500	)		1.30
Unvested - December 31, 2009		430,000		$	0.92
Granted		82,500			1.36
Vested		(430,000	)		0.92
Unvested - December 31, 2010		82,500		$	1.36
Granted		1,246,000			1.60
Vested		(693,000	)		1.57
Forfeited		(38,000	)		1.51
Unvested - December 31, 2011		597,500		$	1.60

As of December 31, 2011, there was $1,803 of unrecognized compensation expense related to the unvested portion of options outstanding. This expense is expected to be recognized over a weighted average period of 0.58 years.

Long-Term Equity Incentive Plan

In May 2010, our shareholders approved the Long-Term Equity Incentive Plan (the “LTIP”), effective March 8, 2010 (the “Effective Date”). Under the LTIP, we may grant Restricted Stock Units (“RSU awards”) or Restricted Stock Awards (“RSA awards”) to the directors, officers, employees and consultants of Vista. The maximum number of our Common Shares that may be reserved for issuance under the LTIP, together with those reserved for issuance under the Plan (as discussed above), is a variable number equal to 10% of our issued and outstanding Common Shares on a non-diluted basis. The total number of Common Shares issuable to our insiders at any time and issued to our insiders within any one-year period under the LTIP, together with any stock options issued under the Plan, shall not exceed 10% of our issued and outstanding Common Shares on a non-diluted basis. The total number of Common Shares issuable to a director under the LTIP shall not exceed the lesser of: (i) 1% of our issued and outstanding Common Shares; and (ii) an annual award value of $100 per director.

The LTIP is administered by the Board of Directors, which can delegate the administration to the Compensation Committee or to such other officers and employees of Vista as designated by the Board of Directors. The Board of Directors will determine the persons to whom awards are made; set the size, type, terms and conditions of the awards; fix the prices (if any) to be paid for the award; interpret the LTIP; adopt, amend, rescind and take all other actions it believes are necessary or advisable for the implementation and administration of the LTIP.

Restricted Stock Units

The estimated fair value of each of our RSU awards was determined on the date of grant based on the closing market price of our Common Shares on the date of grant.

The following table summarizes the RSU activity under the LTIP as of December 31, 2011 and 2010 and changes during the years then ended is set forth in the following table:

	Number of units			Weighted average grant- date fair value
Unvested - December 31, 2008		-		$	-

Unvested - December 31, 2009		-		$	-
Granted		175,500			2.37
Unvested - December 31, 2010		175,500		$	2.37
Forfeited		(10,000	)		2.37
Exercised		(165,500	)		2.37
Granted		960,000			3.84
Unvested - December 31, 2011		960,000		$	3.84

On September 13, 2010, we granted 175,500 RSU awards to employees, directors and consultants of Vista. The market price on the date of grant was $2.37. All of the RSU awards granted vested on the one-year anniversary of the grant date and upon vesting, a holder of an RSU award received one Common Share, for no additional consideration, for each RSU award held.

On November 16, 2011, we granted 960,000 RSU awards to employees, directors and consultants of Vista. The market price on the date of grant was $3.84. 660,000 of the RSU awards granted vest as follows: a) 50% vest after three years; b) 25% vest at the time that a definitive investment decision or significant transaction, as confirmed by the Board, is made for Mt. Todd; c) 12.5% vest upon the completion of a positive preliminary feasibility study for the Guadalupe de los Reyes gold/silver project as set out in a technical report that has been filed on SEDAR at www.sedar.com by the Corporation; and d) 12.5% vest upon the addition of 1.5 million ounces of estimated measured and indicated mineral resources to Vista's resource holdings, which estimated resources are set out in a technical report that has been filed on SEDAR at www.sedar.com by the Corporation. The vesting period for all RSUs shall be at least one year. The remaining 300,000 RSU awards granted vest when the average adjusted value of the Common Shares (or Common Shares plus dividends or distribution value) measured over any consecutive 30-day period is two times the closing trading price of the Common Shares as listed on the NYSE Amex Exchange on November 2, 2011 of $3.78, provided that this period is at least one year. The adjusted value is the closing trading price of the Common Shares as listed on the NYSE Amex Exchange (on any given day) divided by one (1) plus the percentage change (increase/decrease) from date the RSUs were granted to the current date of the average of the AMEX Gold Basket of Unhedged Gold Stocks Index (“HUI”) and the Philadelphia Gold and Silver Sector Index (“XAU”). In the event the share price vesting provision is met prior to the end of one year, the RSUs will vest at the end of one year regardless of the share price at that time. Upon vesting, a holder of an RSU award will receive one Common Share, for no additional consideration, for each RSU award held.

Compensation expense with a fair value of $524 and $126 was recognized during the years ended December 31, 2011 and 2010, respectively, for RSUs previously granted and vesting over time. No RSUs were granted during 2009.

As of December 31, 2011, there was $3,363 of unrecognized compensation expense related to the unvested RSU awards outstanding. This expense is expected to be recognized over a weighted average period of 1.68 years.