9. Additional Paid-in Capital

	Warrants			Stock based compensation		Compensation options			Other paid-in capital		Total additional paid-in capital

As of December 31, 2011		10,288		$	5,065	$	588		$	8,729	$	24,670
Warrant exercise		(464	)		-		-			464		-
Stock options expensed		-			442		-			-		442
Restricted stock units expensed		-			1,550		-			-		1,550
Compensation options exercised		-			-		(294	)		294		-
As of June 30, 2012		9,824		$	7,057	$	294		$	9,487	$	26,662

Warrants

Warrant activity is summarized in the following table:

	Warrants outstanding			Valuation			Weighted average exercise price per share		Weighted average remaining life (yrs.)		Intrinsic value

As of December 31, 2011		15,850,238		$	10,288		$	3.45		3.7	$	485
Exercised		(478,261	)	$	(464	)
As of June 30, 2012		15,371,977		$	9,824		$	3.49		3.3	$	93

The 15,371,977 outstanding warrants expire in the following time frames: 152,175 warrants expire in October 2012 and 15,219,802 expire in October 2015.

Compensation Options

	Compensation options outstanding			Valuation			Expiry date	Weighted average remaining life (yrs.)

As of December 31, 2011		450,000		$	588
Exercise		(225,000	)		(294	)
As of June 30, 2012		225,000		$	294		Apr-13		0.8

In connection with the Offering, Vista granted 450,000 compensation options to the Underwriters as compensation. Each compensation option is exercisable until April 20, 2013 to purchase one common share at the issue price of C$3.30. Our closing price was $2.91 at June 30, 2012.

Stock-Based Compensation

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

	June 30,		December 31,
	2012		2011

Balance, beginning of period	$	5,065	$	4,695
Stock options		442		238
Restricted stock units		1,550		132
Balance, end of period	$	7,057	$	5,065

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% (7,220,714 at June 30, 2012) of the issued and outstanding common shares on a non-diluted basis (72,207,144 shares at June 30, 2012). 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.

A summary of option activity under the Plan as of June 30, 2012 and changes during the quarter 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, 2011		3,195,000	$	3.27		2.73	$	1,039
Outstanding - June 30, 2012		3,195,000		3.27		2.23		792

Exercisable - June 30, 2012		3,017,500	$	3.25		2.12	$	792

The total number of options outstanding at June 30, 2012 is 3,195,000 representing 4.42% of issued capital.

Stock option compensation expense with a fair value of $205 and $735 was recognized during the three months ended June 30, 2012 and 2011, respectively. Stock option compensation expense with a fair value of $442 and $783 was recognized during the six months ended June 30, 2012 and 2011, respectively.

No options were granted for the six months ended June 30, 2012 and 671 options were granted for the six months ended June 30, 2011.

During the six months ended June 30, 2012, no options were exercised. During the six months ended June 30, 2011, options were exercised for an aggregate intrinsic value of $224.

A summary of the status of our unvested stock options as of June 30, 2012 and changes during the period then ended is set forth below:

	Number of shares			Weighted average grant-date fair value per share		Weighted average remaining amortization period (Years)
Unvested - December 31, 2011		597,500		$	1.60
Vested		(420,000	)		1.51
Unvested - June 30, 2012		177,500		$	1.82		0.29

As of June 30, 2012, there was $73 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 0.29 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% (7,220,714 at June 30, 2012) of the issued and outstanding common shares on a non-diluted basis (72,207,144 shares at June 30, 2012).

The LTIP is administered by the Board of Directors, which can delegate the administration to the Compensation Committee of the Board of Directors 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 June 30, 2012 and changes during the period then ended is set forth in the following table:

	Number of units		Weighted average grant-date fair value
Unvested - December 31, 2011		960,000	$	3.84
Granted		350,000		3.07
Unvested - June 30 , 2012		1,310,000	$	3.63

On November 16, 2011, we granted 660,000 RSU awards to employees and consultants of Vista. The market price on the date of grant was $3.84. 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 Company; 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 Company. The vesting period for all RSUs shall be at least one year.

On November 16, 2011, we also granted 300,000 RSU awards to executive management of Vista. The 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 MKT Exchange on November 2, 2011 of $3.78, provided that this period is at least one year after the grant date of the RSUs. The adjusted value is the closing trading price of the common shares as listed on the NYSE MKT 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. If the vesting conditions are not met within 36 months of the date of grant, the RSUs are cancelled and of no further force and effect.

On January 1, 2012, the Board of Directors of Vista were granted a sum of 350,000 RSU awards. 300,000 of the January 1, 2012 grants vest under the same conditions as the 300,000 RSU awards granted to executive management on November 16, 2011 and 50,000 vest one year from the date of grant.

RSU Compensation expense with a fair value of $775 and $1,550 was recognized during the three- and six-month periods ended June 30, 2012. RSU Compensation expense with a fair value of $75 and $165 was recognized during the three- and six-month periods ended June 30, 2011.

As of June 30, 2012, there was $2,955 of unrecognized compensation expense related to the unvested RSU awards outstanding. The expense for unvested RSU awards is expected to be recognized over a weighted average period of 1.32 years.