Sec Form 4 Filing - REID-ANDERSON JAMES @ Six Flags Entertainment Corp - 2015-02-18

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person REID-ANDERSON JAMES 2. Issuer Name and Ticker or Trading Symbol Six Flags Entertainment Corp [ SIX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chairman, President & CEO (Last) (First) (Middle) C/O SIX FLAGS ENTERTAINMENT CORPORATION, 924 AVENUE J EAST 3. Date of Earliest Transaction (MM/DD/YY) 02/18/2015 (Street) GRAND PRAIRIE, TX75050 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.025 per share 02/18/2015 S 43,060 ( 1 ) D $ 46.2691 ( 2 ) 3,123,488 D Common Stock, par value $0.025 per share 02/18/2015 A 526,125 ( 3 ) A $ 0 3,649,613 D Common Stock, par value $0.025 per share 02/18/2015 A 57,940 ( 4 ) A $ 0 3,707,553 D Common Stock, par value $0.025 per share 02/19/2015 S 256,940 ( 1 ) D $ 47.29 ( 5 ) 3,450,613 D Common Stock, par value $0.025 per share 02/19/2015 A 1,520 ( 4 ) A $ 0 3,452,133 D Common Stock, par value $0.025 per share 02/19/2015 M 30,000 A $ 23.53 3,482,133 D Common Stock, par value $0.025 per share 02/19/2015 M 37,500 A $ 40.02 3,519,633 D Common Stock, par value $0.025 per share 02/20/2015 M 62,500 A $ 33.45 3,582,133 D Common Stock, par value $0.025 per share 02/20/2015 A 4,972 ( 4 ) A $ 0 3,587,105 D Common Stock, par value $0.025 per share 500,000 I By GRAT

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Employee Stock Option (Right to Buy) $ 47.6 02/19/2015 A 200,000 ( 6 ) 02/19/2025 Common Stock, par value $.025 per share 200,000 $ 0 200,000 D Employee Stock Option (Right to Buy) $ 23.53 02/19/2015 M 30,000 ( 7 ) 02/17/2022 Common Stock, par value $0.025 per share 30,000 $ 0 30,000 D Employee Stock Option (Right to Buy) $ 40.02 02/19/2015 M 37,500 ( 8 ) 02/19/2024 Common Stock, par value $0.025 per share 37,500 $ 0 112,500 D Employee Stock Option (Right to Buy) $ 33.45 02/20/2015 M 62,500 ( 9 ) 02/20/2023 Common Stock, par value $0.025 per share 62,500 $ 0 125,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other REID-ANDERSON JAMES C/O SIX FLAGS ENTERTAINMENT CORPORATION 924 AVENUE J EAST GRAND PRAIRIE, TX75050 Chairman, President & CEO Signatures /s/ James Reid-Anderson 02/20/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by James Reid-Anderson. ( 2 )The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $46.25 to $46.36, inclusive. The reporting person undertakes to provide Issuer, any security holder of Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. ( 3 )Reflects shares of stock earned for early achievement under the Issuer's Project 500 Performance Award. ( 4 )Grant of shares of common stock pursuant to dividend equivalent rights under Issuer's Long-Term Incentive Plan. The number of shares of common stock granted was based on the conversion of cash dividend equivalents accumulated. ( 5 )The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $46.25 to $48.01, inclusive. The reporting person undertakes to provide Issuer, any security holder of Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. ( 6 )One-fourth of the options will vest on each of the first four anniversaries of February 19, 2015, if the reporting person has been continuously employed with the Issuer through such date, subject to accelerated vesting in certain events, including certain terminations or upon a change of control, or as provided for by the Compensation Committee of the Issuer's Board of Directors. ( 7 )Mr. Reid-Anderson was granted an option to purchase 120,000 shares (as adjusted for stock split) on February 17, 2012, which vests 25% on each of the first four anniversaries of the grant date if the reporting person has been continuously employed with the Issuer through such date, subject to accelerated vesting in certain events, including certain terminations or upon a change in control, or as provided for by the Compensation Committee of the Issuer's Board of Directors. ( 8 )Mr. Reid-Anderson was granted an option to purchase 150,000 shares on February 19, 2014, which vests 25% on each of the first four anniversaries of the grant date if the reporting person has been continuously employed with the Issuer through such date, subject to accelerated vesting in certain events, including certain terminations or upon a change in control, or as provided for by the Compensation Committee of the Issuer's Board of Directors. ( 9 )Mr. Reid-Anderson was granted an option to purchase 250,000 shares (as adjusted for stock split) on February 20, 2013, which vests 25% on each of the first four anniversaries of the grant date if the reportingperson has been continuously employed with the Issuer through such date, subject to accelerated vesting in certain events, including certain terminations or upon a change in control, or as provided for by theCompensation Committee of the Issuer's Board of Directors.

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