Southern Co comptroller sells 100 SO shares

Southern Co’s comptroller reported a small Rule 10b5-1 plan sale of 100 shares, with sizable direct and 401(k) holdings remaining.

Rhea-AI Filing Summary

SOUTHERN CO (SO) reports that Comptroller Matthew M. Kim sold 100 shares of Southern Company Common Stock on September 1, 2026, at $88.45 per share in an open-market or private transaction under a Rule 10b5-1 trading plan. After this sale, he holds 6,399.55 shares directly and 1,222.207 shares indirectly through a 401(k).

Insider Trade Summary 10b5-1

Net Seller: 100 shares

Net Sell 2 txns

Insider Kim Matthew M.

Role Comptroller

Sold 100 shs ($9K)

Type	Security	Shares	Price	Value
Sale	Southern Company Common Stock	100	$88.45	$9K
holding	Southern Company Common Stock	--	--	--

Holdings After Transaction: Southern Company Common Stock — 6,399.55 shares (Direct); Southern Company Common Stock — 1,222.207 shares (Indirect, 401(k))

Key Figures

Shares sold: 100 shares Sale price per share: $88.45 per share Direct holdings after transaction: 6,399.55 shares +2 more

5 metrics

Shares sold 100 shares Southern Company Common Stock sold on September 1, 2026

Sale price per share $88.45 per share Price for the 100 shares sold on September 1, 2026

Direct holdings after transaction 6,399.55 shares Direct ownership of Southern Company Common Stock after the sale

Indirect 401(k) holdings after transaction 1,222.207 shares Indirect ownership through a 401(k) plan after the sale

Net buy/sell shares -100 shares Net effect of reported buy and sell transactions in this Form 4

Key Terms

Rule 10b5-1 trading plan, indirect, 401(k), open-market or private transaction

4 terms

Rule 10b5-1 trading plan regulatory

"transactions were made under a Rule 10b5-1 trading plan"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

indirect financial

"indirect ownership of 1,222.207 shares through a 401(k)"

401(k) financial

"1,222.207 shares indirectly through a 401(k) plan"

A 401(k) is a type of retirement savings plan offered by employers that allows workers to set aside a portion of their paycheck before taxes are taken out. The money saved in a 401(k) can grow over time through investments, helping individuals build funds for their future retirement. It matters to investors because it provides a tax-advantaged way to save and invest for long-term financial security.

open-market or private transaction market

"Sale in open market or private transaction"

FAQ

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

What insider transaction did SOUTHERN CO (SO) report for Matthew M. Kim?

SOUTHERN CO reported that Comptroller Matthew M. Kim sold 100 shares of Southern Company Common Stock on September 1, 2026, in a sale described as an open-market or private transaction.

At what price were the SO shares sold in this Form 4 filing?

The reported sale price was $88.45 per share for the 100 shares of Southern Company Common Stock sold on September 1, 2026.

How many SO shares does Matthew M. Kim hold after the reported sale?

After the sale, Matthew M. Kim holds 6,399.55 shares of Southern Company Common Stock directly and 1,222.207 shares indirectly through a 401(k) plan.

Was the SO insider transaction made under a Rule 10b5-1 trading plan?

Yes. The filing affirms that the reported transactions were made under a Rule 10b5-1 trading plan, indicating they were executed pursuant to a pre-established trading arrangement.

What is Matthew M. Kim’s role at SOUTHERN CO (SO) in this Form 4?

In this Form 4, Matthew M. Kim is identified as an officer of SOUTHERN CO with the title Comptroller. He is not listed as a director or ten percent owner.

How many insider holding entries are disclosed in this SO Form 4?

The Form 4 shows one direct holding of 6,399.55 shares and one indirect holding of 1,222.207 shares held through a 401(k), following the reported sale transaction.

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 09/03/2026 - 10:00 AM EDT Accepted by SEC EDGAR 09/03/2026 - 10:00 AM 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).

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^*

Kim Matthew M.

(Last) (First) (Middle)

30 IVAN ALLEN JR. BLVD., NW

(Street)

ATLANTA GEORGIA 30308

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
SOUTHERN CO [ SO ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Comptroller

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/01/2026

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
Southern Company Common Stock	09/01/2026		S		100	D	$88.45	6,399.55	D
Southern Company Common Stock								1,222.207	I	401(k)

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:

	/s/ Brittney Anderson, Attorney-in-Fact for Matthew M. Kim	09/03/2026
	** 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.
* Form 4: SEC 1474 (03-26)