Post Holdings: Route One reports 6.5% stake

Post Holdings, Inc. ownership disclosure: Route One Investment Company, L.P. and affiliated reporting persons report beneficial ownership of 2,950,568 shares, representing 6.5% of Common Stock based on 45,322,586 shares outstanding as of May 4, 2026.

Rhea-AI Filing Summary

Post Holdings, Inc. ownership disclosure: Route One Investment Company, L.P. and affiliated reporting persons report beneficial ownership of 2,950,568 shares, representing 6.5% of Common Stock based on 45,322,586 shares outstanding as of May 4, 2026.

The filing states the reporting persons have shared voting and shared dispositive power over the 2,950,568 shares and that the Funds hold the shares for their investors; each reporting person disclaims ownership except for pecuniary interest.

Insights

Corporate Governance Analyst

Route One and affiliates disclose a significant passive stake with shared control signals.

Route One, ROIC, the General Partner, and two control persons report beneficial ownership of 2,950,568 shares or 6.5%, using the issuer's outstanding share count of 45,322,586 as of May 4, 2026. The disclosure lists shared voting and shared dispositive power for that position.

Because the filing is a Schedule 13G/A amendment, it signals an ownership reporting obligation rather than an intent to change control; the reporting persons expressly disclaim group membership and control-purpose holdings. Subsequent filings would clarify any active intentions.

Investor Relations Specialist

This filing quantifies a >5% holder and clarifies fund ownership and voting/ disposition structure.

The Funds hold the common stock for investors and may receive dividends or sale proceeds; the filing notes no single Fund exceeds 5%. Signatures by managing members confirm the joint but non‑group filing status.

Market implications depend on holder actions and future disclosures; current text frames the stake as passive with shared authority and pecuniary interest only.

Key Figures

Reported holdings: 2,950,568 shares Percent of class: 6.5% Shares outstanding (denominator): 45,322,586 shares

3 metrics

Reported holdings 2,950,568 shares Beneficial ownership reported by Route One and affiliates

Percent of class <percent>6.5%</percent> Calculated using 45,322,586 shares outstanding as of May 4, 2026

Shares outstanding (denominator) 45,322,586 shares As reported in issuer Form 10-Q for quarter ended March 31, 2026 (basis: May 4, 2026)

Key Terms

Schedule 13G/A, Beneficial ownership, Shared dispositive power

3 terms

Schedule 13G/A regulatory

"Amendment No. 10; Schedule 13G/A cover designation"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficial ownership financial

"Amount beneficially owned: Route One: 2,950,568"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Shared dispositive power financial

"Shared Dispositive Power 2,950,568.00"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What stake does Route One report in Post Holdings (POST)?

Route One and affiliated reporting persons report 2,950,568 shares, equal to 6.5% of Common Stock, using 45,322,586 shares outstanding as of May 4, 2026 as the denominator.

Do the reporting persons claim sole voting or dispositive power over POST shares?

No. The filing shows 0 shares with sole voting or sole dispositive power and 2,950,568 shares with shared voting and shared dispositive power among the reporting persons.

Are these shares held on behalf of funds or individual accounts?

The Funds hold the Common Stock for the benefit of their investors; the filing states the Funds have the right to receive dividends or proceeds, and no individual Fund holds more than 5% of outstanding shares.

Does this Schedule 13G/A indicate an attempt to change control of Post Holdings?

The reporting persons certify the securities were not acquired to change or influence control and disclaim group membership; the filing characterizes the position as not held for control purposes.

Who signed the filing for the reporting persons?

The filing is signed by William F. Duhamel, Jr. as Managing Member and by Jason E. Moment as a reporting person, with dates of signature on 05/14/2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/14/2026 - 03:54 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 10)

Post Holdings, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

737446104

(CUSIP Number)

03/31/2026

(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)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 737446104

1

Names of Reporting Persons

Route One Investment Company, 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 2,950,568.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,950,568.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,950,568.00

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)

6.5 %

12

Type of Reporting Person (See Instructions)

IA, PN

Comment for Type of Reporting Person: Percentage calculated based on 45,322,586 shares of Common Stock outstanding on May 4, 2026, as reported in the Form 10-Q filed by the Issuer for the quarter ended March 31, 2026.

SCHEDULE 13G

CUSIP Number(s): 737446104

1

Names of Reporting Persons

ROIC, 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 2,950,568.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,950,568.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,950,568.00

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)

6.5 %

12

Type of Reporting Person (See Instructions)

HC, OO

Comment for Type of Reporting Person: Percentage calculated based on 45,322,586 shares of Common Stock outstanding on May 4, 2026, as reported in the Form 10-Q filed by the Issuer for the quarter ended March 31, 2026.

SCHEDULE 13G

CUSIP Number(s): 737446104

1

Names of Reporting Persons

Route One Investment Company, 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 2,950,568.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,950,568.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,950,568.00

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)

6.5 %

12

Type of Reporting Person (See Instructions)

HC, OO

Comment for Type of Reporting Person: Percentage calculated based on 45,322,586 shares of Common Stock outstanding on May 4, 2026, as reported in the Form 10-Q filed by the Issuer for the quarter ended March 31, 2026.

SCHEDULE 13G

CUSIP Number(s): 737446104

1

Names of Reporting Persons

William F. Duhamel, Jr.

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 2,950,568.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,950,568.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,950,568.00

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)

6.5 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Percentage calculated based on 45,322,586 shares of Common Stock outstanding on May 4, 2026, as reported in the Form 10-Q filed by the Issuer for the quarter ended March 31, 2026.

SCHEDULE 13G

CUSIP Number(s): 737446104

1

Names of Reporting Persons

Jason E. Moment

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 2,950,568.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,950,568.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,950,568.00

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)

6.5 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Percentage calculated based on 45,322,586 shares of Common Stock outstanding on May 4, 2026, as reported in the Form 10-Q filed by the Issuer for the quarter ended March 31, 2026.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Post Holdings, Inc.
(b)	Address of issuer's principal executive offices: 2503 S. Hanley Road, St. Louis, MO 63144
Item 2.
(a)	Name of person filing: Route One Investment Company, L.P. ("Route One") ROIC, LLC Route One Investment Company, LLC (the "General Partner") William F. Duhamel, Jr. Jason E. Moment Route One is the investment adviser to investment funds (collectively, the "Funds"), and the General Partner is the general partner of one or more of those funds. ROIC, LLC is the general partner of Route One. Mr. Duhamel and Mr. Moment are the control persons of Route One, ROIC, LLC and the General Partner. The reporting persons are filing this Schedule 13G jointly, but not as members of a group, and each disclaims membership in a group. Each reporting person also disclaims beneficial ownership of the Common Stock except to the extent of that person's pecuniary interest therein.
(b)	Address or principal business office or, if none, residence: The principal business office of the reporting persons is: One Letterman Drive, Building D, Suite DM 200, San Francisco, CA 94129
(c)	Citizenship: See Item 4 of the cover sheet for each reporting person.
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 737446104
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: Route One: 2,950,568 ROIC, LLC: 2,950,568 General Partner: 2,950,568 William F. Duhamel, Jr.: 2,950,568 Jason E. Moment: 2,950,568
(b)	Percent of class: Route One: 6.5% ROIC, LLC: 6.5% General Partner: 6.5% William F. Duhamel, Jr.: 6.5% Jason E. Moment: 6.5%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Route One: 0 ROIC, LLC: 0 General Partner: 0 William F. Duhamel, Jr.: 0 Jason E. Moment: 0
	(ii) Shared power to vote or to direct the vote: Route One: 2,950,568 ROIC, LLC: 2,950,568 General Partner: 2,950,568 William F. Duhamel, Jr.: 2,950,568 Jason E. Moment: 2,950,568
	(iii) Sole power to dispose or to direct the disposition of: Route One: 0 ROIC, LLC: 0 General Partner: 0 William F. Duhamel, Jr.: 0 Jason E. Moment: 0
	(iv) Shared power to dispose or to direct the disposition of: Route One: 2,950,568 ROIC, LLC: 2,950,568 General Partner: 2,950,568 William F. Duhamel, Jr.: 2,950,568 Jason E. Moment: 2,950,568
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. The Funds hold the Common Stock for the benefit of their investors and have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock. No individual Fund's holdings of Common Stock are more than five percent of the outstanding Common 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.

Route One Investment Company, L.P.

Signature:	/s/ William F. Duhamel, Jr.
Name/Title:	Managing Member of the General Partner, ROIC, LLC
Date:	05/14/2026

ROIC, LLC

Signature:	/s/ William F. Duhamel, Jr.
Name/Title:	Managing Member
Date:	05/14/2026

Route One Investment Company, LLC

Signature:	/s/ William F. Duhamel, Jr.
Name/Title:	Managing Member
Date:	05/14/2026

William F. Duhamel, Jr.

Signature:	/s/ William F. Duhamel, Jr.
Name/Title:	Reporting Person
Date:	05/14/2026

Jason E. Moment

Signature:	/s/ Jason E. Moment
Name/Title:	Reporting person
Date:	05/14/2026

Exhibit Information

Ex. 99 - Agreement Regarding Joint Filing of Statement on Schedule 13D or 13G