Duke Energy vs Southern (DUK vs SO)
Side by side from their SEC filings: revenue, margins, growth, returns and valuation, plus short interest, insider activity and institutional ownership.
Duke Energy is the larger company by revenue ($31.7B vs $28.9B). Southern carries the larger market value ($102.8B vs $93.3B). Duke Energy has grown revenue faster over the last 4 fiscal years (+29.6% cumulative vs +25.2%). Duke Energy runs the higher operating margin (27.2% vs 25.2%). Duke Energy trades at the lower trailing P/E (18.0x vs 21.2x).
About Duke Energy
Duke Energy is an energy company that provides retail electric service through its regulated public utilities in the Southeast and Midwest regions of the United States. It generates, transmits, distributes, and sells electricity to approximately 8.7 million customers across six states. The company operates a diverse generation portfolio primarily fueled by natural gas, nuclear, and coal, and serves residential, commercial, and industrial customers.
About Southern
Southern Company is a holding company that owns electric utilities and energy service companies primarily serving the Southeastern United States. Its traditional electric operating companies provide retail and wholesale electric service in Alabama, Georgia, and Mississippi. Southern Power develops and operates power generation assets and sells electricity in the wholesale market, while Southern Company Gas distributes natural gas in Illinois, Georgia, Virginia, and Tennessee.
Head to head (DUK FY2025 vs SO FY2025)
| Metric | DUKFY2025 | SOFY2025 |
|---|---|---|
| Revenue | $31.74B | $28.94B |
| Revenue growth (YoY) | 5.6% | 8.3% |
| Gross margin | — | — |
| Operating margin | 27.2% | 25.2% |
| Net margin | 15.7% | 15.0% |
| Net income | $4.97B | $4.34B |
| Diluted EPS | $6.31 | $3.92 |
| FCF margin | -5.3% | -10.1% |
| ROE | 9.4% | 11.2% |
| Long-term debt / equity | 1.51× | 1.69× |
| Market cap | $93.28B | $102.82B |
| P/E | 18.0× | 21.2× |
Fundamentals are from each company’s SEC filings (DUK FY2025, SO FY2025). ROE is net income over fiscal-year-end equity; long-term debt / equity counts non-current term debt only. P/E and market cap are derived from stored market prices, last retrieved on a rolling basis and typically within the past week.
Five-year trend (as reported)
| Revenue | FY2021 | FY2022 | FY2023 | FY2024 | FY2025 |
|---|---|---|---|---|---|
| DUK | $24.49B | $28.68B | $28.67B | $30.05B | $31.74B |
| SO | $23.11B | $25.94B | $24.83B | $26.72B | $28.94B |
Peer standing
Where each company ranks among the 86 Utilities companies, on the same scale. Each figure is ranked only against peers that report it. Percentiles describe position in the distribution, not a rating.
| Metric | DUK | SO |
|---|---|---|
| Operating margin | 27.2%79th percentile of 77 | 25.2%74th percentile of 77 |
| Net margin | 15.7%71st percentile of 80 | 15.0%68th percentile of 80 |
| FCF margin | -5.3%55th percentile of 66 | -10.1%40th percentile of 66 |
| Revenue growth (YoY) | +5.6%36th percentile of 82 | +8.3%43rd percentile of 82 |
| ROE | 9.4%59th percentile of 81 | 11.2%79th percentile of 81 |
| P/E | 18.0×30th percentile of 74 | 21.2×62nd percentile of 74 |
| Long-term debt / equity | 1.51×76th percentile of 77 | 1.69×83rd percentile of 77 |
| Short interest (days to cover) | 4.00d45th percentile of 86 | 4.17d47th percentile of 86 |
Short interest
| FINRA settlement data | DUK | SO |
|---|---|---|
| Shares sold short | 17.8M | 29.3M |
| Change vs prior settlement | -6.5% | +1.3% |
| Days to cover | 4.00 | 4.17 |
| As of settlement | 2026-09-30 | 2026-09-30 |
Source: FINRA Consolidated Short Interest. FINRA is the owner and source of the FINRA-supplied data; republishing or redistributing it is not permitted. Not presented as a percentage of float. No FINRA endorsement of this product is implied.
Insider activity (last 90 days)
| Form 4 activity (codes P/S) | DUK | SO |
|---|---|---|
| Buys | 0 | 0 |
| Sells | 0 | 6 ($842,258) |
Non-derivative purchases (code P) and sales (code S) reported on SEC Form 4, which may be open-market or private (grants, exercises and tax withholding excluded). For context, about 15% of covered companies saw any reported insider purchase (code P) in a 90-day window.
Held by the same investors
7 tracked 13F managers hold both Duke Energy and Southern as of their latest quarterly filings: AQR Capital Management, Bridgewater Associates, Citadel Advisors, D. E. Shaw, Gotham Asset Management, Millennium Management, Two Sigma Investments. See which superinvestors hold your own portfolio with the smart money checker.
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Data sourced from SEC EDGAR. Figures are as-reported and may be unaudited or restated; verify against the source filings before relying on them. Comparisons are descriptive (higher or lower on a reported figure), not a rating or a recommendation. Informational only. Not investment advice.