Post Holdings CFO receives 18,024 performance shares

The award payout was based on relative total shareholder return percentile rank over a performance period from October 1, 2023, through September 30, 2026.

Rhea-AI Filing Summary

Matthew J. Mainer, Post Holdings, Inc.’s EVP, CFO & Treasurer, acquired 18,024 common shares on October 22, 2026, upon payout of an earned performance share award under a shareholder-approved equity plan. The payout was based on relative total shareholder return percentile rank for the performance period from October 1, 2023, through September 30, 2026. Mainer also surrendered 7,940 shares for tax withholding due to vesting of the 18,024 PRSUs; the reported price was $78.06 per share.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider MAINER MATTHEW J

Role EVP, CFO & TREASURER

Type	Security	Shares	Price	Value
Grant/Award	Common Stock F1	18,024	$0.00	$0.00
Tax Withholding	Common Stock F2	7,940	$78.06	$620K

Holdings After Transaction: Common Stock — 84,754 shares (Direct)

Footnotes (2)

1. F1. Acquisition of shares pursuant to Rule 16b-3 upon payout of earned performance share award (PRSUs) under a shareholder approved equity plan. The payout was based on the level of achievement of the performance goal of relative total shareholder return percentile rank for the performance period October 1, 2023 through September 30, 2026.
2. F2. Surrender of shares in payment of tax withholding due as a result of the vesting of 18,024 PRSUs in accordance with Rule 16b-3.

Key Figures

Performance award shares acquired: 18,024 shares Shares surrendered for tax withholding: 7,940 shares Reported per-share price: $78.06 per share +1 more

4 metrics

Performance award shares acquired 18,024 shares Upon payout on October 22, 2026

Shares surrendered for tax withholding 7,940 shares Due to vesting of the 18,024 PRSUs on October 22, 2026

Reported per-share price $78.06 per share Shares surrendered for tax withholding

Performance period October 1, 2023, through September 30, 2026 Award payout based on relative total shareholder return percentile rank

Key Terms

performance share award (PRSUs), Rule 16b-3, relative total shareholder return percentile rank

3 terms

performance share award (PRSUs) technical

"payout of earned performance share award (PRSUs)"

Rule 16b-3 regulatory

"pursuant to Rule 16b-3"

Rule 16b-3 is a Securities and Exchange Commission regulation that exempts certain routine, pre-approved transactions by company insiders from automatic liability for short-term trading profits. It acts like a safe harbor: if an insider follows a formal plan or the board approves specific transactions in advance, profits from buying and selling company stock within six months are not automatically reclaimed. Investors care because the rule clarifies when insider trades are permissible and reduces uncertainty about potential clawbacks.

relative total shareholder return percentile rank technical

"performance goal of relative total shareholder return percentile rank"

FAQ

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

How many POST shares did Matthew J. Mainer acquire and surrender?

On October 22, 2026, Matthew J. Mainer acquired 18,024 common shares upon payout of earned performance share awards and surrendered 7,940 shares for tax withholding when the 18,024 PRSUs vested. The reported price for the surrendered shares was $78.06 per share.

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

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 10/26/2026 - 04:42 PM EDT Accepted by SEC EDGAR 10/26/2026 - 04:42 PM EDT Learn about SEC filing dates

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

MAINER MATTHEW J

(Last) (First) (Middle)

C/O POST HOLDINGS, INC.

2503 S. HANLEY ROAD

(Street)

ST. LOUIS MISSOURI 63144

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Post Holdings, Inc. [ POST ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, CFO & TREASURER

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/22/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	10/22/2026		A		18,024(1)	A	$0	92,694	D
Common Stock	10/22/2026		F		7,940(2)	D	$78.06	84,754	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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Acquisition of shares pursuant to Rule 16b-3 upon payout of earned performance share award (PRSUs) under a shareholder approved equity plan. The payout was based on the level of achievement of the performance goal of relative total shareholder return percentile rank for the performance period October 1, 2023 through September 30, 2026.

2. Surrender of shares in payment of tax withholding due as a result of the vesting of 18,024 PRSUs in accordance with Rule 16b-3.

Remarks:

	/s/ Diedre J. Gray, Attorney-in-Fact	10/26/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)