The Southern Company
MX ˙ BMV ˙ US8425871071
SecurityMX:SO / The Southern Company
InstitutionSecond Line Capital, LLC
Latest Disclosed Ownership11,453 shares
Latest Disclosed Value $ 1,107,469
Second Line Capital, LLC reports 7.13% increase in ownership of SO / The Southern Company

On May 15, 2026 - Second Line Capital, LLC filed a 13F-HR form disclosing ownership of 11,453 shares of The Southern Company (MX:SO) valued at $1,107,469 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 10,691 shares of The Southern Company. This represents a change in shares of 7.13% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F SOUTHERN CO COM Stock 842587107 11,453 762 7.13 1,107 18.78 0.2098
2026-02-17 2025-12-31 13F SOUTHERN COM 842587107 10,691 -286 -2.61 932 -10.38 0.1916
2025-11-19 2025-09-30 13F SOUTHERN COM 842587107 10,977 3 0.03 1,040 3.28 0.2153
2025-08-18 2025-06-30 13F SOUTHERN COM 842587107 10,974 113 1.04 1,008 0.90 0.2341
2025-05-15 2025-03-31 13F SOUTHERN COM 842587107 10,861 -1,112 -9.29 999 1.32 0.2574
2025-02-14 2024-12-31 13F SOUTHERN COM 842587107 11,973 1,348 12.69 986 2.82 0.2657
2024-11-19 2024-09-30 13F SOUTHERN COM 842587107 10,625 -546 -4.89 958 10.62 0.2611
2024-08-16 2024-06-30 13F SOUTHERN COM 842587107 11,171 2,895 34.98 867 46.04 0.2651
2024-05-22 2024-03-31 13F SOUTHERN COM 842587107 8,276 1,357 19.61 594 22.27 0.1926
2024-02-09 2023-12-31 13F SOUTHERN COM 842587107 6,919 6,919 485 0.1941
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.