Kim Matthew M. 4

4 · SOUTHERN CO · Filed Apr 2, 2026

AI-generated summary of this filing

Updated Apr 2, 2026

Southern Co (SO) Comptroller Matthew M. Kim Exercises RSUs, Shares Withheld

What Happened

Matthew M. Kim, Comptroller of Southern Company (SO), had restricted stock units (derivatives) convert/vest on April 1, 2026. The filing shows 82 shares were acquired via exercise/conversion and then 82 shares were delivered to the company to cover FICA withholding at $96.94 per share (total value withheld $7,949). In addition, three other derivative conversions/settlements show 13, 23 and 42 shares disposed (net-settled/withheld) at $0.

Key Details

Transaction date: 2026-04-01; Form 4 filed: 2026-04-02 (filed the next day).
Withholding price: $96.94 per share for the 82-share withholding (total $7,949).
Shares acquired (conversion/vesting): 82 shares. Shares surrendered/withheld: 82 shares (for FICA) and 13 + 23 + 42 = 78 additional shares net-settled at $0.
Footnotes: withholdings relate to FICA/tax obligations and retirement-eligibility rules; one footnote notes inclusion of 4 accrued dividend equivalent units. The underlying awards are RSUs granted Jan 31, 2024; Feb 5, 2025; and Feb 11, 2026, with vesting schedules and share withholding to satisfy income tax requirements.
Shares owned after the transaction are not shown in the provided data.
Filing appears timely (reported on the next business day).

Context

These transactions reflect RSU vesting and net-share settlement/withholding to satisfy tax and FICA obligations (transaction codes M = exercise/conversion of derivative; F = payment of exercise price or tax liability). This is a routine withholding action on vested equity rather than an open-market sale or a cash purchase.

Form 4

Period: 2026-04-01

Comptroller

Transactions

Exercise/Conversion
Southern Company Common Stock
[F1]
2026-04-01+82→ 6,970 total
Tax Payment
Southern Company Common Stock
[F2]
2026-04-01$96.94/sh−82$7,949→ 6,888 total
Exercise/Conversion
Southern Co Restricted Stock Units
[F3]
2026-04-01−13→ 305 total
Exercise: $0.00→ Southern Company Common Stock (13 underlying)
Exercise/Conversion
Southern Co Restricted Stock Units
[F4]
2026-04-01−23→ 539 total
Exercise: $0.00→ Southern Company Common Stock (23 underlying)
Exercise/Conversion
Performance Restricted Stock Units
[F5]
2026-04-01−42→ 975 total
Exercise: $0.00→ Southern Company Common Stock (42 underlying)

Footnotes (5)

[F1]Represents shares delivered to the Company to cover FICA withholding obligations due because Reporting Person is retirement eligible pursuant to his applicable stock grant documents. Includes 4 accrued dividend equivalent units.
[F2]Represents shares delivered to the Company to cover FICA withholding obligations due because Reporting Person is retirement eligible pursuant to his applicable stock grant documents.
[F3]Represents restricted stock units granted on January 31, 2024, payable in Southern Company common stock and will continue to vest on the third anniversary of the grant date. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy income tax requirements.
[F4]Represents restricted stock units granted on February 5, 2025, payable in Southern Company common stock and will continue to vest on the remaining second and third anniversary of the grant date. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy income tax requirements.
[F5]Represents restricted stock units granted on February 11, 2026, payable in Southern Company common stock and vest every year on the first, second and third anniversary of the grant date. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy income tax requirements.

Signature

/s/ Brittney Anderson, Attorney-in-Fact for Matthew M. Kim|2026-04-02

1 file