[SCHEDULE 13G/A] Six Flags Entertainment Corporation/NEW Amended Passive Investment Disclosure

Rhea-AI Filing Summary

Morgan Stanley has reported a significant passive stake in Six Flags Entertainment Corporation. As of the event date of 12/31/2025, Morgan Stanley and its affiliate Morgan Stanley Capital Services LLC together report beneficial ownership of 9,198,875 shares of Six Flags common stock, representing 9.1% of the outstanding class.

The filing shows shared voting power over 9,112,482 shares and shared dispositive power over 9,198,875 shares, with no sole voting or dispositive power. The reporting persons certify the holdings are in the ordinary course of business and not for the purpose of changing or influencing control of Six Flags.

Insights

Equity ownership and governance analyst

Morgan Stanley reports a 9.1% passive stake in Six Flags.

Morgan Stanley and Morgan Stanley Capital Services LLC disclose beneficial ownership of 9,198,875 Six Flags common shares, or 9.1% of the class, as of the 12/31/2025 event date. Voting and dispositive powers are shared rather than held solely.

The reporting persons certify the position is held in the ordinary course of business and not to change or influence control of Six Flags. The filing also notes that it covers only certain Morgan Stanley operating units, with other units, if any, treated separately.

This type of Schedule 13G/A generally signals a sizeable but passive institutional holding. Actual market impact depends on future portfolio decisions by these Morgan Stanley units, which are not described here and would appear in later ownership updates if they occur.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Six Flags Entertainment Corporation/NEW

(Name of Issuer)

Common Stock

(Title of Class of Securities)

83001C108

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 83001C108

1

Names of Reporting Persons

Morgan Stanley

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 9,112,482.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 9,198,875.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

9,198,875.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

9.1 %

12

Type of Reporting Person (See Instructions)

HC, CO

SCHEDULE 13G

CUSIP No. 83001C108

1

Names of Reporting Persons

Morgan Stanley Capital Services LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 8,976,352.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 8,976,352.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

8,976,352.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

8.8 %

12

Type of Reporting Person (See Instructions)

BD, CO

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Six Flags Entertainment Corporation/NEW
(b)	Address of issuer's principal executive offices: 8701 RED OAK BLVD., CHARLOTTE, NC, 28217
Item 2.
(a)	Name of person filing: 1: Morgan Stanley 2: Morgan Stanley Capital Services LLC
(b)	Address or principal business office or, if none, residence: 1: 1585 Broadway, New York, NY 10036 ;2: 1585 Broadway, New York, NY 10036
(c)	Citizenship: 1: Delaware 2: Delaware
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 83001C108
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: See the response(s) to Item 9 on the attached cover page(s).
(b)	Percent of class: 9.1 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See the response(s) to Item 5 on the attached cover page(s).
	(ii) Shared power to vote or to direct the vote: See the response(s) to Item 6 on the attached cover page(s).
	(iii) Sole power to dispose or to direct the disposition of: See the response(s) to Item 7 on the attached cover page(s).
	(iv) Shared power to dispose or to direct the disposition of: See the response(s) to Item 8 on the attached cover page(s).
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit 99.2
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. * In Accordance with the Securities and Exchange Commission Release No. 34-39538 (January 12, 1998) (the "Release"), this filing reflects the securities beneficially owned, or that may be deemed to be beneficially owned, by certain operating units (collectively, the "MS Reporting Units") of Morgan Stanley and its subsidiaries and affiliates (collectively, "MS"). This filing does not reflect securities, if any, beneficially owned by any operating units of MS whose ownership of securities is disaggregated from that of the MS Reporting Units in accordance with the Release.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Morgan Stanley

Signature:	Chris O'Hara
Name/Title:	Authorized Signatory, Morgan Stanley
Date:	02/12/2026

Morgan Stanley Capital Services LLC

Signature:	Chris O'Hara
Name/Title:	Authorized Signatory, Morgan Stanley Capital Services LLC
Date:	02/12/2026

Exhibit Information

EXHIBIT NO. EXHIBITS ------------------ ------------------------------------ 99.1 Joint Filing Agreement 99.2 Item 7 Information * Attention. Intentional misstatements or omissions of fact constitute federal criminal violations (see 18 U.S.C. 1001).