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 ($108.8B vs $97.8B). 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 (19.3x vs 24.7x).
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% |
| Debt / equity | 1.5× | 1.7× |
| Market cap | $97.82B | $108.75B |
| P/E (TTM) | 19.3× | 24.7× |
Fundamentals are from each company’s SEC filings (DUK FY2025, SO FY2025). P/E and market cap are derived from recent market prices and update daily.
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 98 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%78th percentile of 86 | 25.2%72nd percentile of 86 |
| Net margin | 15.7%71st percentile of 91 | 15.0%69th percentile of 91 |
| FCF margin | -5.3%47th percentile of 76 | -10.1%33rd percentile of 76 |
| Revenue growth (YoY) | +5.6%35th percentile of 94 | +8.3%43rd percentile of 94 |
| ROE | 9.4%59th percentile of 89 | 11.2%77th percentile of 89 |
| P/E (TTM) | 19.3×30th percentile of 82 | 24.7×64th percentile of 82 |
| Debt / equity | 1.51×73rd percentile of 84 | 1.69×83rd percentile of 84 |
| Short interest (days to cover) | 4.21d59th percentile of 98 | 4.51d65th percentile of 98 |
Short interest
| FINRA settlement data | DUK | SO |
|---|---|---|
| Shares sold short | 18.0M | 37.4M |
| Change vs prior settlement | +15.3% | +22.7% |
| Days to cover | 4.21 | 4.51 |
| As of settlement | 2026-06-30 | 2026-06-30 |
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 open-market activity | DUK | SO |
|---|---|---|
| Buys | 0 | 0 |
| Sells | 2 ($2.9M) | 3 ($28,350) |
Open-market purchases and sales reported on SEC Form 4 (grants, exercises and tax withholding excluded). For context, about 16% of covered companies saw any open-market insider buy 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, Citadel Advisors, D. E. Shaw, Gotham Asset Management, Millennium Management, Renaissance Technologies, Two Sigma Investments. See which superinvestors hold your own portfolio with the smart money checker.
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Data sourced from SEC EDGAR (public domain). 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.