Cummiskey Christopher 4

4 · SOUTHERN CO · Filed Feb 3, 2026

AI-generated summary of this filing

Updated Feb 3, 2026

Southern Co (SO) EVP Christopher Cummiskey Receives RSU Awards

What Happened

Christopher Cummiskey, Executive Vice President of Southern Co (SO), had performance restricted stock units (PRSUs) vest across Jan 31 and Feb 1, 2026. A total of 3,509 shares were converted to common stock upon vesting (1,794 on Jan 31 and 1,715 on Feb 1). To satisfy tax withholding obligations, 758 shares (valued at $67,697) and 834 shares (valued at $74,485) were withheld, totaling 1,592 shares and $142,182. The transactions are reported as conversions/settlements of derivative awards (code M) with withholding for taxes (code F).

Key Details

Transaction dates and prices:
- Jan 31, 2026: 1,794 RSUs converted to 1,794 shares (acquired at $0); 758 shares withheld @ $89.31 ($67,697).
- Feb 1, 2026: 1,715 RSUs converted to 1,715 shares (acquired at $0); 834 shares withheld @ $89.31 ($74,485).
- Additional derivative entries (1,537 and 1,674 units) reflect related RSU tranches as noted in footnotes.
Net new shares from these vestings (after withholding): 3,509 − 1,592 = 1,917 shares added to Cummiskey’s holdings from these events.
Shares owned after transaction: Not specified in the provided filing excerpt.
Footnotes: Vesting relates to the second 1/3 of PRSUs granted Jan 31, 2024 and the final 1/3 of PRSUs granted Feb 1, 2023; amounts include accrued dividend equivalents and note that shares were withheld to satisfy tax requirements (see F1–F5).
Filing timeliness: Report filed Feb 3, 2026; no late filing indication provided in the excerpt.

Context

These were not open-market sales or purchases but routine settlement of performance-based RSUs. The withholding of shares to pay tax liabilities is common in RSU vestings and does not necessarily indicate a buy or sell signal. The entries labeled M indicate conversion/exercise of derivative awards (RSUs) into shares; entries labeled F indicate shares withheld for tax withholding.

Form 4

Period: 2026-01-31

EVP

Transactions

Exercise/Conversion
Southern Company Common Stock
[F1]
2026-01-31+1,794→ 24,296.442 total
Tax Payment
Southern Company Common Stock
[F2]
2026-01-31$89.31/sh−758$67,697→ 23,538.442 total
Exercise/Conversion
Southern Company Common Stock
[F3]
2026-02-01+1,715→ 25,253.442 total
Tax Payment
Southern Company Common Stock
[F2]
2026-02-01$89.31/sh−834$74,485→ 24,419.442 total
Exercise/Conversion
Performance Restricted Stock Units
[F4]
2026-02-01−1,537→ 0 total
Exercise: $0.00→ Southern Company Common Stock (1,537 underlying)
Exercise/Conversion
Performance Restricted Stock Units
[F5]
2026-01-31−1,674→ 1,674 total
Exercise: $0.00→ Southern Company Common Stock (167 underlying)

Holdings

Footnotes (5)

[F1]Shares acquired upon vesting of second 1/3 of performance restricted stock units granted on January 31, 2024. Includes 120 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 178 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 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.

Signature

/s/ Brittney Anderson, Attorney-in-Fact for Christopher Cummiskey|2026-02-03

1 file