Filed Pursuant to Rule 424(b)(3)
Registration No. 333-155800

August 2011 Performance Update

The Frontier Fund Supplement Dated August 31, 2011 to Prospectus Dated April 30, 2011.

The Frontier Fund Class 3

T H E    F R O N T I E R    F U N D ’ S    G O A L : To provide you – the investor – with a managed futures product that, over the long term, provides attractive returns, reduces volatility, and improves the overall performance of your investment portfolio.

August performance for the various Series of The Frontier Fund is detailed below:*

The Frontier Fund Class 3	August 31, 2011	August 31, 2011	NAV / Unit
	MTD	YTD
Balanced Series-3a	-5.48%	-6.90%	$124.44
Long Only Commodity Series-3	0.08%	2.41%	$106.38
Long/Short Commodity Series-3	-1.06%	12.27%	$172.05
Managed Futures Index Series-3	7.41%	0.03%	$126.76

Additional information, including monthly rates of return, concerning the aforementioned Series and the Trading Advisor(s) is contained in the Prospectus and the respective Series Appendix to the Prospectus.

* The above table sets forth the actual performance for the Class and Series as of August 31, 2011. Actual gross trading performance (gross realized and unrealized gain/loss before deduction for trading commissions and fees, management fees, any other expense, and before addition of interest income) is adjusted for the trading expenses, management fees, initial service fees, on-going service fees, and interest income of the applicable Series.

THIS INSERT MUST BE ACCOMPANIED OR PRECEDED BY THE CURRENT PROSPECTUS OF THE FRONTIER FUND

PAST PERFORMANCE IS NOT INDICATIVE OF FUTURE RESULTS

THE FRONTIER FUND BALANCED SERIES - 3a

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

August 31, 2011

(Unaudited)

						Current Period
INCOME
Realized trading gain/(loss)						$	(126,675.42	)
Unrealized trading gain/(loss)							(14,394.51	)
Less: commissions							(4,340.60	)
Less: FCM fees							(1,175.75	)
Foreign currency gain/(loss)							(818.83	)
Interest income							3,204.35
Total Income							(144,200.76	)
EXPENSES
Trading Fee							7,165.07
Management fees							2,831.13
Incentive fees							14,570.54
Total Expenses							24,566.74
Net Income (Loss)							$(168,767.50)
STATEMENT OF CHANGES IN NET ASSET VALUE
	Units		Dollars			$'s per unit
Net Asset Value, end of prior month		23,518.13973	$	3,096,410.40			131.66
Current month additions		—		—
Current month redemptions		(918.61313)		(115,328.24)
Net Income (loss) for current month				(168,767.50	)
Net Asset Value, end of current month		22,599.52660	$	2,812,314.66			124.44
		Monthly rate of return					-5.48	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/    S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund - Balanced Series 3a

THE FRONTIER LONG ONLY COMMODITY SERIES - 3

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

August 31, 2011

(Unaudited)

						Current Period
INCOME
Realized trading gain/(loss)						$	16,946.85
Unrealized trading gain/(loss)							133.69
Less: commissions							—
Less: FCM fees							(375.50	)
Foreign currency gain/(loss)							—
Interest income							1,913.21
Total Income							18,618.25
EXPENSES
Management Fees							1,141.02
Incentive fees							—
Total Expenses							1,141.02
Net Income (Loss)							$17,477.23
STATEMENT OF CHANGES IN NET ASSET VALUE
	Units		Dollars			$'s per unit
Net Asset Value, end of prior month		5,904.24597	$	627,632.42			106.30
Current month additions		5,438.77641		555,055.86
Current month redemptions		(1,575.89417)		(161,097.40	)
Net Income (loss) for current month				17,477.23
Net Asset Value, end of current month		9,767.12821	$	1,039,068.11			106.38
		Monthly rate of return					0.08	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/    S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund - Long Only Commodity Series 3

THE FRONTIER FUND LONG/SHORT COMMODITY SERIES - 3

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

August 31, 2011

(Unaudited)

							Current Period
INCOME
Realized trading gain/(loss)							$	3,159,571.68
Unrealized trading gain/(loss)								(3,325,922.72	)
Less: commissions								(16,127.85	)
Less: FCM fees								(10,914.04	)
Foreign currency gain/(loss)								(506.73	)
Interest income								44,192.76
Total Income								(149,706.90	)
EXPENSES
Management fees								128,410.86
Incentive fees								(49,214.88	)
Total Expenses								79,195.98
Net Income (Loss)							$	(228,902.88	)
STATEMENT OF CHANGES IN NET ASSET VALUE
	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		139,092.10464		$	24,188,278.61			173.90
Current month additions		10,621.30238			1,792,528.67
Current month redemptions		(4,832.50237	)		(824,519.61	)
Net Income (loss) for current month					(228,902.88	)
Net Asset Value, end of current month		144,880.90465		$	24,927,384.79			172.05
		Monthly rate of return						-1.06	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/    S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund - Long/Short Commodity Series 3

THE FRONTIER FUND MANAGED FUTURES INDEX SERIES - 3

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

August 31, 2011

(Unaudited)

					Current Period
INCOME
Realized trading gain/(loss)					$	36,384.92
Unrealized trading gain/(loss)						(10,841.76	)
Less: commissions						(71.10	)
Less: FCM fees						(169.10	)
Foreign currency gain/(loss)						238.25
Interest income						652.13
Total Income						26,193.34
EXPENSES
Management fees						891.37
Incentive fees						—
Total Expenses						891.37
Net Income (Loss)					$	25,301.97
STATEMENT OF CHANGES IN NET ASSET VALUE
	Units		Dollars		$'s per unit
Net Asset Value, end of prior month		2,893.44645	$	341,481.96		118.02
Current month additions		—		—
Current month redemptions		—		—
Net Income (loss) for current month				25,301.97
Net Asset Value, end of current month		2,893.44645	$	366,783.93		126.76
		Monthly rate of return				7.41	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/    S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund - Managed Futures Index Series 3