Ameren (NYSE: AEE) CEO sells 26,818 shares, reports tax share withholding

Rhea-AI Filing Summary

Ameren Corp Chairman, President & CEO Martin J. Lyons reported multiple stock transactions in Ameren common shares. He completed an open-market sale of 26,818 shares at $111.84 per share under a Rule 10b5-1 trading plan, leaving him with 282,681 directly held shares afterward.

On a prior date, 28,154 shares were withheld by the issuer at $113.28 per share to cover tax obligations tied to vesting performance share units and restricted stock units. The filing also notes 2,116 share equivalents held indirectly through the Ameren Corporation Savings Investment Plan’s unitized stock fund as of February 28, 2026.

Insider Trade Summary

Net Seller: 26,818 shares ($2,999,325)

Net Sell 3 txns

Insider LYONS MARTIN J

Role Chairman, President & CEO

Sold 26,818 shs ($3.00M)

Type	Security	Shares	Price	Value
Sale	Common Stock, $.01 Par Value	26,818	$111.84	$3.00M
Tax Withholding	Common Stock, $.01 Par Value	28,154	$113.28	$3.19M
holding	Common Stock, $.01 Par Value	--	--	--

Holdings After Transaction: Common Stock, $.01 Par Value — 282,681 shares (Direct); Common Stock, $.01 Par Value — 2,116 shares (Indirect, By 401(K))

Footnotes (1)

1. Represents the estimated number of share equivalents held by the reporting person in the unitized stock fund included in the Ameren Corporation Savings Investment Plan as of February 28, 2026. Shares withheld by the issuer to satisfy tax withholding obligations arising in connection with the vesting of performance share units and restricted stock units. Shares sold pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

Form 4 Insider Transactions: What Each Field Means →

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).

X

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^*

LYONS MARTIN J

(Last) (First) (Middle)

P.O. BOX 66149

(Street)

ST. LOUIS MO 63166-6149

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
AMEREN CORP [ AEE ]

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

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chairman, President & CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

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

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

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

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, $.01 Par Value								2,116(1)	I	By 401(K)
Common Stock, $.01 Par Value	02/27/2026		F		28,154	D	$113.28	309,499(2)	D
Common Stock, $.01 Par Value	03/03/2026		S		26,818	D	$111.84	282,681(3)	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. Represents the estimated number of share equivalents held by the reporting person in the unitized stock fund included in the Ameren Corporation Savings Investment Plan as of February 28, 2026.

2. Shares withheld by the issuer to satisfy tax withholding obligations arising in connection with the vesting of performance share units and restricted stock units.

3. Shares sold pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

Remarks:

	Jonathan T. Shade, Deputy Corp. Secy. of Ameren Corporation, attorney-in-fact for Martin J. Lyons, Jr.	03/03/2026
	** 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.

FAQ

What insider transactions did Ameren (AEE) CEO Martin J. Lyons report?

Martin J. Lyons reported an open-market sale of 26,818 Ameren shares at $111.84 each and a tax-withholding disposition of 28,154 shares at $113.28. He also reported indirect holdings via a Savings Investment Plan stock fund.

How many Ameren (AEE) shares did the CEO sell in the latest Form 4?

The CEO sold 26,818 shares of Ameren common stock in an open-market transaction at $111.84 per share. This sale was executed under a Rule 10b5-1 trading plan adopted by the reporting person, indicating it was pre-arranged rather than discretionary.

Were any Ameren (AEE) shares withheld for taxes in this Form 4?

Yes. 28,154 Ameren shares were withheld by the issuer to satisfy tax withholding obligations upon vesting of performance share units and restricted stock units, at a price of $113.28 per share. This reflects a tax-related disposition rather than an open-market sale.

How many Ameren (AEE) shares does the CEO hold after these transactions?

After the reported open-market sale, the CEO directly holds 282,681 Ameren common shares. In addition, the filing notes 2,116 share equivalents held indirectly through the Ameren Corporation Savings Investment Plan’s unitized stock fund as of February 28, 2026.

Is the Ameren (AEE) CEO’s share sale part of a Rule 10b5-1 plan?

Yes. The 26,818-share sale was executed pursuant to a Rule 10b5-1 trading plan adopted by the CEO. Such plans allow pre-scheduled transactions, helping separate routine diversification or liquidity needs from discretionary trading decisions.

What indirect Ameren (AEE) holdings did the CEO report in the Form 4?

The CEO reported 2,116 share equivalents held indirectly through the unitized stock fund in the Ameren Corporation Savings Investment Plan as of February 28, 2026. These are estimated share equivalents rather than directly held common stock certificates.