Sterling A. Spainhour Jr. - 31 Jan 2026 Form 4 Insider Report for SOUTHERN CO (SO)

Role
EVP & CLO
Signature
/s/ Brittney Anderson, Attorney-in-Fact for Sterling A. Spainhour
Issuer symbol
SO
Transactions as of
31 Jan 2026
Net transactions value
-$209,789
Form type
4
Filing time
03 Feb 2026, 18:18:25 UTC
Previous filing
02 Oct 2025
Next filing
13 Feb 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Spainhour Sterling A Jr. EVP & CLO 30 IVAN ALLEN JR BLVD NW, ATLANTA /s/ Brittney Anderson, Attorney-in-Fact for Sterling A. Spainhour 03 Feb 2026 0001849295

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction SO Southern Company Common Stock Options Exercise $0 +2,755 +16% $0.000000 20,137 31 Jan 2026 Direct F1
transaction SO Southern Company Common Stock Tax liability $115,299 -1,291 -6.4% $89.31 18,846 31 Jan 2026 Direct F2
transaction SO Southern Company Common Stock Options Exercise $0 +2,371 +13% $0.000000 21,217 01 Feb 2026 Direct F3
transaction SO Southern Company Common Stock Tax liability $94,490 -1,058 -5% $89.31 20,159 01 Feb 2026 Direct F2
holding SO Southern Company Common Stock 6,876 31 Jan 2026 401(k)

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction SO Performance Restricted Stock Units Holding Options Exercise $0 -2,124 -100% $0.000000 0 01 Feb 2026 Southern Company Common Stock 2,124 $0.000000 Direct F4
transaction SO Performance Restricted Stock Units Options Exercise $0 -2,571 -50% $0.000000 2,571 31 Jan 2026 Southern Company Common Stock 2,571 $0.000000 Direct F5
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Shares acquired upon vesting of second 1/3 of performance restricted stock units granted on January 31, 2024. Includes 184 accrued dividend equivalent units.
F2 Shares withheld to satisfy required state and federal tax withholding requirements.
F3 Shares acquired upon vesting of final 1/3 of performance restricted stock units granted on February 1, 2023. Includes 247 accrued dividend equivalent units.
F4 Represents final 1/3 of performance restricted stock units granted on February 1, 2023. Each restricted stock unit represents the right to receive, at settlement, one share of common stock. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy tax requirements.
F5 Represents second 1/3 of performance restricted stock units granted on January 31, 2024. The remaining award will vest in 2027. Each restricted stock unit represents the right to receive, at settlement, one share of common stock. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy tax requirements.