485BPOS

SECURITIES AND EXCHANGE COMMISSION

Washington, D. C.  20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

¨

Pre-Effective Amendment No.

¨

Post-Effective Amendment No.

 92

ý

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT

¨

OF 1940

Amendment No.

93

ý

(Check appropriate box or boxes.)

Mutual Fund Series Trust - File Nos. 333-132541 and 811-21872

(Exact Name of Registrant as Specified in Charter)

17605 Wright Street, Omaha, Nebraska 68130

(Address of Principal Executive Offices)                (Zip Code)

Registrant’s Telephone Number, including Area Code:   (402) 895-1600

CT CORPORATION SYSTEM

1300 EAST NINTH STREET

CLEVELAND, OH 44114

(Name and Address of Agent for Service)

With copy to:

JoAnn M. Strasser, Thompson Hine LLP

41 South High Street, Suite 1700, Columbus, Ohio 44114-1291

Approximate Date of Proposed Public Offering:  

It is proposed that this filing will become effective:

ýimmediately upon filing pursuant to paragraph (b)

¨  on [date] pursuant to paragraph (b)

¨ 60 days after filing pursuant to paragraph (a)(1)

¨ on (date) pursuant to paragraph (a)(1)

¨ 75 days after filing pursuant to paragraph (a)(2)

¨ on (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

¨ this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act and Investment Company Act, the Registrant certifies that it meets all of the requirement for effectiveness of this registration statement under rule 485(b) under the Securities Act and has duly caused this Post-Effective Amendment to the Registration Statement on Form N-1A to be signed on its behalf by the undersigned, duly authorized in the City of Columbus, State of Ohio, on the 16th day of October, 2012.

Mutual Fund Series Trust

By:

/s/ JoAnn M. Strasser

JoAnn M. Strasser

Attorney-in-Fact

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following person in the capacities indicated on the 16th day of October, 2012 or as otherwise indicated.

Dr. Bert Pariser*, Trustee

Tobias Caldwell*, Trustee

Jerry Szilagyi, Trustee/President/Principal Executive Officer*  

Erik  Naviloff, Treasurer/Principal Financial Officer *

Tiberiu Weisz*, Trustee

*By:

/s/ JoAnn M. Strasser

JoAnn M. Strasser

Attorney-in-Fact

Exhibit Index

Index No.

Description of Exhibit

EX-101.INS

XBRL Instance Document

EX-101.SCH

XBRL Taxonomy Extension Schema Document

EX-101.CAL

XBRL

Taxonomy Extension Calculation Linkbase

EX-101.DEF

XBRL Taxonomy Extension Definition Linkbase

EX-101.LAB

XBRL Taxonomy Extension Labels Linkbase

EX-101.PRE

XBRL Taxonomy Extension Presentation Linkbase

XML

Catalyst Insider Buying Fund

Investment Objective:

The Fund's goal is to achieve long-term capital appreciation.

Fees and Expenses of the Fund:

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.  You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund.  More information about these and other discounts is available from your financial professional and in the section entitled How to Buy Shares on page 6 of the Fund’s Prospectus.

Shareholder Fees

(fees paid directly from your investment)

Shareholder Fees (USD $)	Catalyst Insider Buying Fund Class C
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Maximum Deferred Sales Charge (Load) (as a % of the original purchase price)	1.00%
Maximum Sales Charge (Load) Imposed on Reinvested Dividends and other Distributions	none
Redemption Fee	none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Catalyst Insider Buying Fund Class C
Management Fees		1.25%
Distribution and/or Service (12b-1) Fees		1.00%
Other Expenses	[1]	0.40%
Total Annual Fund Operating Expenses		2.65%
Fee Waiver and/or Expense Reimbursement	[2]	(0.40%)
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		2.25%

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.  The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then redeem all of your shares at the end of those periods.  The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same.  Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example (USD $)	Expense Example, with Redemption, 1 Year	Expense Example, with Redemption, 3 Years
Catalyst Insider Buying Fund Class C	328	786

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio).  A higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account.  These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund's performance.

Principal Investment Strategies:

The Fund seeks to achieve its investment objective by investing primarily in common stocks of U.S. companies, and buying and selling put and call options of U.S. companies.  The Fund will purchase positions in stocks that are experiencing significant insider buying by corporate executives and directors.  Catalyst Capital Advisors LLC (the “Advisor”) generally considers insider buying to be significant when three or more executives or directors of a company have recently purchased a total of at least 10,000 shares of their company stock. The Fund may invest in companies of any market capitalization, including smaller-sized companies.

The Advisor uses public information that is filed with the Securities and Exchange Commission (“SEC”) on corporate insider buying and selling activity for its investment decisions. The Advisor’s research and quantitative back testing of insider trading data over long periods of time has resulted in the development of a proprietary method of analyzing insider trading activity that it believes can provide long-term capital appreciation. The underlying thesis is that corporate insiders know more about the prospects of the company they run than anybody else.

The Advisor’s investment process focuses on insider identities (position in the company), motivations, insider trading trends, trading volumes, firm size and other factors to select stocks for the portfolio. Stocks are sold when the relevant insider trading trends reverse or when portfolio positions achieve or no longer provide the targeted risk adjusted return.

The Fund is classified as “non-diversified” for purposes of the Investment Company Act of 1940 (the “1940 Act”), which means that it is not limited by the 1940 Act with regard to the portion of its assets that may be invested in the securities of a single issuer.

Principal Risks of Investing in the Fund:

As with any mutual fund, there is no guarantee that the Fund will achieve its goal. The Fund's net asset value and returns will vary and you could lose money on your investment in the Fund.

Limited History of Operations. The Fund is a new or relatively new mutual fund and has a limited history of operations.

Management Risk.  The portfolio manager’s judgments about the attractiveness, value and potential appreciation of particular stocks or other securities in which the Fund invests may prove to be incorrect and there is no guarantee that the portfolio manager’s judgment will produce the desired results. 

Market Risk.  Overall stock market risks may also affect the value of the Fund.  Factors such as domestic economic growth and market conditions, interest rate levels and political events affect the securities markets.

Non-diversification Risk. Because a relatively high percentage of a non-diversified Fund’s assets may be invested in the securities of a limited number of companies that could be in the same or related economic sectors, the Fund’s portfolio may be more susceptible to any single economic, technological or regulatory occurrence than the portfolio of a diversified fund.

Options Risk.  There are risks associated with the sale and purchase of call and put options.  As the buyer of a put option, the Fund assumes the risk of a rise in the market price of the underlying security above the exercise price of the option which will cause a loss of the premium paid for the option.

Security Risk.  The value of the Fund may decrease in response to the activities and financial prospects of an individual security in the Fund’s portfolio.

Smaller Capitalization Stock Risk.  To the extent the Fund invests in the stocks of smaller-sized companies, the Fund may be subject to additional risks, including the risk that earnings and prospects of these companies are more volatile than larger companies.  Smaller-sized companies may experience higher failure rates than larger companies and normally have a lower trading volume than larger companies, which may tend to make their market price fall more disproportionately than larger companies in response to selling pressures.

Performance:

Because the Fund is a new fund and does not yet have a full calendar of investment operations, no performance information is presented for the Fund at this time.  In the future, performance information will be presented in this section of this Prospectus. Updated performance information will be available at no cost by calling 1-866-447-4228.

[1] Estimated for the current fiscal year.

[2] The Advisor has contractually agreed to waive fees and/or reimburse expenses of the Fund through October 31, 2013. This agreement may be terminated by the Fund's Board of Trustees on 60 days' written notice to the Advisor.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Document Type

dei_DocumentType

485BPOS

Document Period End Date

dei_DocumentPeriodEndDate

Sep. 29, 2012

Registrant Name

dei_EntityRegistrantName

Mutual Fund Series Trust

Central Index Key

dei_EntityCentralIndexKey

0001355064

Amendment Flag

dei_AmendmentFlag

false

Prospectus Date

rr_ProspectusDate

Sep. 29, 2012

Catalyst Insider Buying Fund

Risk/Return:

rr_RiskReturnAbstract

Objective [Heading]

rr_ObjectiveHeading

Investment Objective:

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund's goal is to achieve long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses of the Fund:

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.  You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund.  More information about these and other discounts is available from your financial professional and in the section entitled How to Buy Shares on page 6 of the Fund’s Prospectus.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees

(fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover:

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio).  A higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account.  These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund's performance.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example:

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.  The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then redeem all of your shares at the end of those periods.  The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same.  Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund seeks to achieve its investment objective by investing primarily in common stocks of U.S. companies, and buying and selling put and call options of U.S. companies.  The Fund will purchase positions in stocks that are experiencing significant insider buying by corporate executives and directors.  Catalyst Capital Advisors LLC (the “Advisor”) generally considers insider buying to be significant when three or more executives or directors of a company have recently purchased a total of at least 10,000 shares of their company stock. The Fund may invest in companies of any market capitalization, including smaller-sized companies.

The Advisor uses public information that is filed with the Securities and Exchange Commission (“SEC”) on corporate insider buying and selling activity for its investment decisions. The Advisor’s research and quantitative back testing of insider trading data over long periods of time has resulted in the development of a proprietary method of analyzing insider trading activity that it believes can provide long-term capital appreciation. The underlying thesis is that corporate insiders know more about the prospects of the company they run than anybody else.

The Advisor’s investment process focuses on insider identities (position in the company), motivations, insider trading trends, trading volumes, firm size and other factors to select stocks for the portfolio. Stocks are sold when the relevant insider trading trends reverse or when portfolio positions achieve or no longer provide the targeted risk adjusted return.

The Fund is classified as “non-diversified” for purposes of the Investment Company Act of 1940 (the “1940 Act”), which means that it is not limited by the 1940 Act with regard to the portion of its assets that may be invested in the securities of a single issuer.

Risk [Heading]

rr_RiskHeading

Principal Risks of Investing in the Fund:

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As with any mutual fund, there is no guarantee that the Fund will achieve its goal. The Fund's net asset value and returns will vary and you could lose money on your investment in the Fund.

Limited History of Operations. The Fund is a new or relatively new mutual fund and has a limited history of operations.

Management Risk.  The portfolio manager’s judgments about the attractiveness, value and potential appreciation of particular stocks or other securities in which the Fund invests may prove to be incorrect and there is no guarantee that the portfolio manager’s judgment will produce the desired results. 

Market Risk.  Overall stock market risks may also affect the value of the Fund.  Factors such as domestic economic growth and market conditions, interest rate levels and political events affect the securities markets.

Non-diversification Risk. Because a relatively high percentage of a non-diversified Fund’s assets may be invested in the securities of a limited number of companies that could be in the same or related economic sectors, the Fund’s portfolio may be more susceptible to any single economic, technological or regulatory occurrence than the portfolio of a diversified fund.

Options Risk.  There are risks associated with the sale and purchase of call and put options.  As the buyer of a put option, the Fund assumes the risk of a rise in the market price of the underlying security above the exercise price of the option which will cause a loss of the premium paid for the option.

Security Risk.  The value of the Fund may decrease in response to the activities and financial prospects of an individual security in the Fund’s portfolio.

Smaller Capitalization Stock Risk.  To the extent the Fund invests in the stocks of smaller-sized companies, the Fund may be subject to additional risks, including the risk that earnings and prospects of these companies are more volatile than larger companies.  Smaller-sized companies may experience higher failure rates than larger companies and normally have a lower trading volume than larger companies, which may tend to make their market price fall more disproportionately than larger companies in response to selling pressures.

Risk Lose Money [Text]

rr_RiskLoseMoney

The Fund's net asset value and returns will vary and you could lose money on your investment in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance:

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

Because the Fund is a new fund and does not yet have a full calendar of investment operations, no performance information is presented for the Fund at this time.  In the future, performance information will be presented in this section of this Prospectus. Updated performance information will be available at no cost by calling 1-866-447-4228.

Catalyst Insider Buying Fund | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum Deferred Sales Charge (Load) (as a % of the original purchase price)

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

Maximum Sales Charge (Load) Imposed on Reinvested Dividends and other Distributions

rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther

none

Redemption Fee

rr_RedemptionFee

none

Management Fees

rr_ManagementFeesOverAssets

1.25%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.40%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.65%

Fee Waiver and/or Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.40%)

^[2]

Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement

rr_NetExpensesOverAssets

2.25%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

328

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

786

[1] Estimated for the current fiscal year.

[2] The Advisor has contractually agreed to waive fees and/or reimburse expenses of the Fund through October 31, 2013. This agreement may be terminated by the Fund's Board of Trustees on 60 days' written notice to the Advisor.