Sec Form 4 Filing - EnerVest, Ltd. @ Magnolia Oil & Gas Corp - 2018-08-16

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 EnerVest, Ltd. 2. Issuer Name and Ticker or Trading Symbol Magnolia Oil & Gas Corp [ MGY] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1001 FANNIN STREET, SUITE 800 3. Date of Earliest Transaction (MM/DD/YY) 08/16/2018 (Street) HOUSTON, TX77002 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 Class A Common Stock 08/16/2018 A 1,243,630 ( 1 ) A $ 0 33,034,554 ( 2 ) ( 3 ) ( 4 ) D

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 Class B Common Stock ( 6 ) 08/16/2018 A 3,256,370 ( 5 ) ( 6 ) ( 7 ) Class A Common Stock 87,195,804 $ 0 87,195,804 ( 3 ) ( 4 ) ( 8 ) ( 9 ) ( 10 ) D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other EnerVest, Ltd. 1001 FANNIN STREET SUITE 800 HOUSTON, TX77002 X EnerVest Management GP, L.C. 1001 FANNIN STREET, SUITE 800 HOUSTON, TX77002 X EnerVest Energy Institutional Fund XIV-A, L.P. 1001 FANNIN STREET SUITE 800 HOUSTON, TX77002 X EnerVest Energy Institutional Fund XIV-2A, L.P. 1001 FANNIN STREET SUITE 800 HOUSTON, TX77002 X EnerVest Energy Institutional Fund XIV-3A, L.P. 1001 FANNIN STREET SUITE 800 HOUSTON, TX77002 X EnerVest Energy Institutional Fund XIV-WIC, L.P. 1001 FANNIN STREET, SUITE 800 HOUSTON, TX77002 X EnerVest Energy Institutional Fund XIV-C, L.P. 1001 FANNIN STREET SUITE 800 HOUSTON, TX77002 X EnerVest Energy Institutional Fund XIV-C-AIV, L.P. 1001 FANNIN STREET, SUITE 800 HOUSTON, TX77002 X EnerVest Investment Services, L.L.C. 1001 FANNIN STREET SUITE 800 HOUSTON, TX77002 X Signatures /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd., the sole member of EVFA GP XIV, LLC, the Managing General Partner of EnerVest Energy Institutional Fund XIV-A, L.P. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd., the sole member of EVFA XIV-2A, LLC, the Managing General Partner of EnerVest Energy Institutional Fund XIV-2A, L.P. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd., the sole member of EVFA XIV-3A, LLC, the Managing General Partner of EnerVest Energy Institutional Fund XIV-3A, L.P. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd., the sole member of EnerVest Holding XIV, LLC, the Managing General Partner of EnerVest Energy Institutional Fund XIV-WIC, L.P. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd., the sole member of EVFC GP XIV, LLC, the Managing General Partner of EnerVest Energy Institutional Fund XIV-C, L.P. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Chief Executive Officer, EnerVest Management GP, L.C., the General Partner of EnerVest, Ltd., the sole member of EVFC GP XIV, LLC, the Managing General Partner of EnerVest Energy Institutional Fund XIV-C-AIV, L.P. 08/24/2018 Signature of Reporting Person Date /s/ John B. Walker, Executive Chairman, EnerVest Operating, L.L.C., the General Partner of EnerVest Holding, L.P., the sole member of EnerVest Investment Services, L.L.C. 08/24/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents 1,243,630 shares of Class A Common Stock ("Class A Common Stock") issued to EnerVest Energy Institutional Fund XIV-C, L.P. ("EV XIV-C") on August 16, 2018 as a portion of earnout consideration payable in connection with Magnolia Oil & Gas Corporation's (the "Company") business combination with EnerVest, Ltd.'s South Texas Division (the "Business Combination"). ( 2 )EV XIV-C owns of record 33,034,554 shares of Class A Common Stock. ( 3 )EnerVest Management GP, L.C. ("EVM GP") is the general partner of EnerVest, Ltd. ("Enervest"), which is the sole member, with sole control over the actions of, each of, EVFA GP XIV, LLC, EVFA XIV-2A, LLC, EVFA XIV-3A, LLC, and EnerVest Holding XIV, LLC, the managing general partners, respectively, of EnerVest Energy Institutional Fund XIV-A, L.P. ("EV XIV-A"), EnerVest Energy Institutional Fund XIV-2A, L.P. ("EV XIV-2A"), EnerVest Energy Institutional Fund XIV-3A, L.P. ("EV XIV-3A"), and EnerVest Energy Institutional Fund XIV-WIC, L.P. ("EV XIV-WIC"). EnerVest is also the sole member, with sole control over the actions of, EVFC GP XIV, LLC, the managing general partner of each of EV XIV-C and EnerVest Energy Institutional Fund XIV-C-AIV, L.P. ("EV XIV-C-AIV"). EnerVest Investment Services, L.L.C. ("EIS, LLC") is the investment advisor for EV XIV-A, EV XIV-2A, EV XIV-3A, EV XIV-WIC, EV XIV-C and EV XIV-C-AIV (such six entities together, the "Record Holders" and each, a "Record Holder"). ( 4 )Each Record Holder and each of EVM GP, EnerVest, EVFA GP XIV, LLC, EVFA XIV-2A, LLC, EVFA XIV-3A, LLC, EnerVest Holding XIV, LLC, EVFC GP XIV, LLC, and EIS, LLC (collectively, the "Non-Fund Entities") directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by the Record Holders and, therefore, a "ten percent holder" hereunder. Each Record Holder and each Non-Fund Entity disclaims beneficial ownership of the shares reported herein, except to the extent of its pecuniary interest therein, and, with respect to each of the Record Holders, except to the extent of its respective direct ownership reported herein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes. ( 5 )Represents (i) 2,165,520 shares of Class B Common Stock issued to EV XIV-A, (ii) 22,620 shares of Class B Common Stock issued to EV XIV-WIC, (iii) 402,100 shares of Class B Common Stock issued to EV XIV-2A, (iv) 424,240 shares of Class B Common Stock issued to EV XIV-3A and (v) 241,890 shares of Class B Common Stock issued to EV XIV-C-AIV, each issued on August 16, 2018 as a portion of earnout consideration payable in connection with the Business Combination. ( 6 )Shares of Class B Common Stock, when combined with an equal number of units ("Units") of Magnolia Oil & Gas Parent LLC, a Delaware limited liability company, in which the Company is the managing member, are exchangeable from time to time at the option of the holders thereof for shares of Class A Common Stock on a one-for-one basis (or, at the Issuer's option, for cash). ( 7 )Not applicable. ( 8 )Represents the aggregate number of shares of Class B Common Stock issued to each of EV XIV-A, EV XIV-2A, EV XIV-3A, EV XIV-WIC, and EV XIV-C-AIV in connection with the Business Combination and earnout consideration. (EV XIV-C's shares of Class A Common Stock, together with the shares of Class B Common Stock and Units held by EV XIV-A, EV XIV-2A, EV XIV-3A, EV XIV-WIC, and EV XIV-C-AIV, are collectively referred to herein as the "Equity Interests.") ( 9 )EV XIV-A owns of record 57,522,774 shares of Class B Common Stock; EV XIV-2A owns of record 11,416,615 shares of Class B Common Stock; EV XIV-3A owns of record 11,229,851 shares of Class B Common Stock; EV XIV-WIC owns of record 600,919 shares of Class B Common Stock; and EV XIV-C-AIV owns of record 6,425,645 shares of Class B Common Stock. ( 10 )Each Record Holder and each of the Non-Fund Entities directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the Equity Interests owned by the Record Holders and, therefore, a "ten percent holder" hereunder. Each Record Holder and each Non-Fund Entity disclaims beneficial ownership of the Equity Interests reported herein, except to the extent of its pecuniary interest therein, and, with respect to each of the Record Holders, except to the extent of its respective direct ownership reported herein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes.

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