Southern Co Officer Matthew Kim Files Form 144 to Sell 100 Shares Under 10b5-1 Plan

Executive Summary

On September 1, 2026, Matthew Kim, an Officer of The Southern Company ($SO), filed Form 144 disclosing a notice of proposed sale of 100 shares of common stock through Merrill Lynch with an estimated market value of $8,845 (~$88.45 per share).

Key Transaction Details

• Security: Common Stock
• Shares to Sell: 100 shares
• Aggregate Market Value: $8,845
• Acquisition Origin: Acquired on February 27, 2024, via performance stock vest (compensatory payment) directly from the issuer.
• Trading Plan: The proposed sale is executed pursuant to a pre-arranged Rule 10b5-1 trading plan adopted on November 25, 2025.
• Past 3 Months Sales History:
  • August 3, 2026: 100 shares sold for gross proceeds of $9,428
  • July 1, 2026: 100 shares sold for gross proceeds of $9,577
  • June 1, 2026: 100 shares sold for gross proceeds of $9,116

Market & Governance Context

The filing reflects regular, automated monthly selling activity of 100 shares under a pre-established 10b5-1 plan. Given the negligible transaction size relative to the company's outstanding share count (1,150,362,966 shares), this filing has minimal market impact and presents a Low trading significance rating.