Darlington discloses 5.1% passive Six Flags (FUN) stake in 13G/A

Rhea-AI Filing Summary

Darlington Partners Capital Management and related entities report owning 5,200,000 shares, or 5.1%, of Six Flags Entertainment common stock. This percentage is based on 101,474,349 shares outstanding as of October 31, 2025. All reporting persons share voting and dispositive power over these shares and have no sole authority.

Darlington acts as investment adviser to private funds, including Darlington Partners, L.P., whose clients are entitled to dividends and sale proceeds. The filers state the holdings are in the ordinary course of business and certify they are not seeking to change or influence control of Six Flags.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 3)

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

Darlington Partners Capital Management, LP

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 5,200,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,200,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,200,000.00

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)

5.1 %

12

Type of Reporting Person (See Instructions)

IA, PN

Comment for Type of Reporting Person: Percentage calculated based on 101,474,349 shares of Common Stock outstanding on October 31, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 28, 2025.

SCHEDULE 13G

CUSIP No. 83001C108

1

Names of Reporting Persons

Darlington Partners GP, 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 5,200,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,200,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,200,000.00

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)

5.1 %

12

Type of Reporting Person (See Instructions)

HC, OO

Comment for Type of Reporting Person: Percentage calculated based on 101,474,349 shares of Common Stock outstanding on October 31, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 28, 2025.

SCHEDULE 13G

CUSIP No. 83001C108

1

Names of Reporting Persons

Darlington Partners, L.P.

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 5,200,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,200,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,200,000.00

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)

5.1 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Percentage calculated based on 101,474,349 shares of Common Stock outstanding on October 31, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 28, 2025.

SCHEDULE 13G

CUSIP No. 83001C108

1

Names of Reporting Persons

Scott W. Clark

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 5,200,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,200,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,200,000.00

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)

5.1 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Percentage calculated based on 101,474,349 shares of Common Stock outstanding on October 31, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 28, 2025.

SCHEDULE 13G

CUSIP No. 83001C108

1

Names of Reporting Persons

Ramsey B. Jishi

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 5,200,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,200,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,200,000.00

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)

5.1 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Percentage calculated based on 101,474,349 shares of Common Stock outstanding on October 31, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 28, 2025.

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, NORTH CAROLINA 28217
Item 2.
(a)	Name of person filing: Darlington Partners Capital Management, LP, a Delaware limited partnership ("DPCM LP") Darlington Partners GP, LLC, a Delaware limited liability company ("DP GP") Darlington Partners, L.P., a Delaware limited Darlington ("Darlington") Scott W. Clark Ramsey B. Jishi DPCM LP is the investment adviser of private investment funds, including Darlington (together, the "Funds"). DP GP is the general partner of DPCM LP and the Funds. Mr. Clark and Mr. Jishi are the managers of DP GP. The Filers are filing this Schedule 13G jointly but not as members of a group, and each disclaims membership in a group. Each reporting person disclaims beneficial ownership of Common Stock except to the extent of that person's pecuniary interest therein. In addition, the filing of this Schedule 13G on behalf of Darlington should not be construed as an admission that it is, and it disclaims that it is, a beneficial owner, as defined in Rule 13d-3 under the Act, of any Common Stock covered by this Schedule 13G.
(b)	Address or principal business office or, if none, residence: 300 Drakes Landing Road, Suite 290, Greenbrae, CA 94904
(c)	Citizenship: See Item 4 of the cover sheet for each reporting person.
(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: DPCM LP: 5,200,000 DP GP: 5,200,000 Darlington: 5,200,000 Scott W. Clark: 5,200,000 Ramsey B. Jishi: 5,200,000
(b)	Percent of class: DPCM LP: 5.1% DP GP: 5.1% Darlington: 5.1% Scott W. Clark: 5.1% Ramsey B. Jishi: 5.1%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: DPCM LP: 0 DP GP: 0 Darlington: 0 Scott W. Clark: 0 Ramsey B. Jishi: 0
	(ii) Shared power to vote or to direct the vote: DPCM LP: 5,200,000 DP GP: 5,200,000 Darlington: 5,200,000 Scott W. Clark: 5,200,000 Ramsey B. Jishi: 5,200,000
	(iii) Sole power to dispose or to direct the disposition of: DPCM LP: 0 DP GP: 0 Darlington: 0 Scott W. Clark: 0 Ramsey B. Jishi: 0
	(iv) Shared power to dispose or to direct the disposition of: DPCM LP: 5,200,000 DP GP: 5,200,000 Darlington: 5,200,000 Scott W. Clark: 5,200,000 Ramsey B. Jishi: 5,200,000
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.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. DPCM LP's clients, including Darlington, have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Stock. No individual client's holdings of the Stock, other than those of Darlington, are more than five percent of the outstanding Stock.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
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. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above 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.

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.

Darlington Partners Capital Management, LP

Signature:	/s/ Scott W. Clark
Name/Title:	Manager of Darlington Partners GP, LLC, general partner of Darlington Partners Capital Management, LP
Date:	01/31/2026

Darlington Partners GP, LLC

Signature:	/s/ Scott W. Clark
Name/Title:	Manager
Date:	01/31/2026

Darlington Partners, L.P.

Signature:	/s/ Scott W. Clark
Name/Title:	Manager of Darlington Partners GP, LLC, general partner of Darlington Partners, L.P.
Date:	01/31/2026

Scott W. Clark

Signature:	/s/ Scott W. Clark
Name/Title:	Reporting person
Date:	01/31/2026

Ramsey B. Jishi

Signature:	/s/ Ramsey B. Jishi
Name/Title:	Reporting person
Date:	01/30/2026

Exhibit Information

Exhibit 99.1 - Agreement Regarding Joint Filing of Statement on Schedule 13D or 13G

FAQ

What ownership stake in Six Flags does Darlington report for FUN shareholders?

Darlington and related filers report beneficial ownership of 5,200,000 shares of Six Flags common stock, equal to 5.1% of the class. The percentage is calculated using 101,474,349 shares outstanding as of October 31, 2025, as disclosed by the company.

Is Darlington’s Six Flags (FUN) position passive or activist?

The filing characterizes Darlington’s position as passive. The filers certify the securities were acquired and are held in the ordinary course of business and state they were not obtained for the purpose of changing or influencing control of Six Flags, subject to limited nomination-related activities.

Which entities and individuals are reporting Six Flags holdings in this FUN Schedule 13G/A?

The reporting persons are Darlington Partners Capital Management, LP, Darlington Partners GP, LLC, Darlington Partners, L.P., and individuals Scott W. Clark and Ramsey B. Jishi. Each is shown as beneficially owning 5,200,000 shares, or 5.1% of Six Flags common stock.

How much voting and dispositive power does Darlington report over Six Flags (FUN) shares?

Each reporting person shows 0 shares with sole voting or dispositive power and 5,200,000 shares with shared voting and shared dispositive power. This means decisions to vote or sell the Six Flags shares are made jointly under the investment and fund structures described.

On what share count is Darlington’s 5.1% Six Flags (FUN) ownership based?

The 5.1% ownership figure is calculated using 101,474,349 shares of Six Flags common stock outstanding as of October 31, 2025. That share count comes from Six Flags’ Form 10-Q for the quarter ended September 28, 2025, referenced in the filing.

Who ultimately benefits from Darlington’s Six Flags (FUN) holdings?

The economic benefit belongs to LP’s clients, including Darlington. The filing states these clients have the right to receive dividends and sale proceeds from the Six Flags stock. No individual client, other than Darlington itself, holds more than 5% of the outstanding common stock.

What date triggered this amended Six Flags (FUN) Schedule 13G/A filing?

The event date requiring this Schedule 13G/A amendment is listed as December 31, 2025. This date marks the ownership status being reported, with signatures dated in late January 2026 to certify the information about the Six Flags common stock position.