Constellation Energy Corporation (CEG)
Constellation Energy is the largest US operator of carbon-free nuclear power plants and sells clean electricity.
Utilities stock comparison
CEG vs SO: how the two businesses compare
- Bigger business: SO, with $29.6B of yearly revenue, about 1.2× CEG's $25.5B.
- More profitable: SO keeps 15 cents of each sales dollar as profit, against 9 cents at CEG.
- More cash from each sale: SO turns 33 cents of each sales dollar into operating cash flow, against 17 cents at CEG.
From each company's latest annual SEC filing. Fiscal years can end on different dates.
Southern (SO) is the larger business by reported revenue: $29.6B in its fiscal year ended Dec 2025, about 1.2× CEG's $25.5B (fiscal year ended Dec 2025). CEG's net margin was 9.1% and SO's 14.7%. Both file with the SEC under the same industry code, SIC 4911 (Electric Services).
Figures come from each company's own SEC filings. This page compares the businesses; it is not a price target or a verdict.
- Sector
- Utilities
- SEC industry
- Electric Services
- Same classification
- Fiscal year ends
- December 31
- Same calendar
- Reviewed
- Feb 24, 2026
CEG vs SO: quick comparison
| Company fact | CEG | SO |
|---|---|---|
| Company | Constellation Energy Corporation | The Southern Company |
| Exchange | NASDAQ | NYSE |
| Headquarters | — | Atlanta, Georgia |
| Founded | — | 1945 |
| SEC industry | Electric Services | Electric Services |
| Fiscal year-end | December 31 | December 31 |
| Latest annual filing | 10-K · 2026-02-24 | 10-K · 2026-02-19 |
CEG vs SO: audited financials
- Scale: SO's $29.6B of revenue is about 1.2× CEG's $25.5B.
- Net margin: SO kept 14.7% of revenue as net income versus 9.1% at CEG.
- Cash conversion: operating cash flow equalled CEG 16.6% of revenue, or 1.83× net income; SO 33.2% of revenue, or 2.26× net income. A ratio well above 1× usually reflects non-cash charges or working-capital release; well below 1× can reflect working-capital build or non-cash gains.
- Periods: both fiscal years end on 2025-12-31, so these annual figures cover the same months.
| Metric | CEG | SO |
|---|---|---|
| Revenue | $25.5B2025-01-01 to 2025-12-31 · SEC filing | $29.6B2025-01-01 to 2025-12-31 · SEC filing |
| Net income | $2.3B2025-01-01 to 2025-12-31 · SEC filing | $4.3B2025-01-01 to 2025-12-31 · SEC filing |
| Operating cash flow | $4.2B2025-01-01 to 2025-12-31 · SEC filing | $9.8B2025-01-01 to 2025-12-31 · SEC filing |
| Diluted EPS | $7.402025-01-01 to 2025-12-31 · SEC filing | $3.922025-01-01 to 2025-12-31 · SEC filing |
| Net margin | 9.1%2025-01-01 to 2025-12-31 · SEC filing | 14.7%2025-01-01 to 2025-12-31 · SEC filing |
CEG: FY ending 2025-12-31 · SO: FY ending 2025-12-31. Figures as tagged in each issuer's SEC XBRL filing; fiscal calendars may not align.
Where CEG and SO overlap, and where they don't
Overlap
- Same SEC industry: both report under SIC 4911, Electric Services.
- Shared research theme: Rates & central banks.
- Same fiscal calendar: both fiscal years end December 31.
Differences
- Only CEG maps to Artificial intelligence.
- Profitability: net margin of 9.1% for CEG versus 14.7% for SO.
Overlap is drawn from SEC classifications and Yield Theory research themes. It is not evidence that the companies sell to the same customers or compete product for product.
The Southern Company (SO)
Southern Company provides regulated electricity and natural gas across several southeastern states. It recently completed new nuclear units, expanding its low-carbon generation base.
What moves each company
Company-specific drivers maintained by Yield Theory. Use them to decide which filing deserves deeper work; they are not predictions.
What moves CEG
We have not yet published a company-specific driver list for CEG. The primary source is Item 1 (Business) and Item 1A (Risk Factors) of its 10-K filed 2026-02-24.
What moves SO
We have not yet published a company-specific driver list for SO. The primary source is Item 1 (Business) and Item 1A (Risk Factors) of its 10-K filed 2026-02-19.
The investment question
You now know SO reports about 1.2× CEG's revenue, and SO keeps more of each dollar as net income. Those are the facts. The investment question is what each share price already assumes about their exposure to rates & central banks, and which evidence in the next filings would prove that assumption wrong.
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Read the full researchSEC filing comparison and disclosure evidence
Start with primary filings because fiscal calendars and accounting presentation can make superficially similar quarters incomparable. Both fiscal years end December 31, so annual reports line up, but check segment definitions before comparing growth or margins.
The current verified House and Senate snapshot contains 13 matched transaction rows for CEG and 6 matched transaction rows for SO. These delayed, range-based disclosures can identify a filing to inspect; they do not establish motive, conviction, or a real-time trading signal.
CEG primary filings
SO primary filings
What this comparison cannot tell you
This page does not contain licensed live prices, a valuation model, earnings estimates, portfolio constraints, or a forecast of future returns. SEC classifications can be broad, company descriptions can lag strategic change, and the latest annual filing may predate a material acquisition or divestiture. Read subsequent quarterly and current reports before making a decision.
A stronger business is not automatically the better stock. Starting valuation, expectations, capital structure, cyclicality, dilution, and the probability of each thesis determine the investment outcome. Use this comparison to frame the work, then verify the numbers in the linked filings and current company disclosures.
More comparisons involving CEG or SO
CEG vs SO FAQs
Are CEG and SO direct competitors?
Constellation Energy and Southern share the SEC industry classification “Electric Services.” That makes the operating comparison relevant, but it does not prove that every product, customer, or revenue stream competes directly.
Is CEG or SO the bigger company by revenue?
Southern (SO) is the larger business by reported revenue: $29.6B in its fiscal year ended Dec 2025, about 1.2× CEG's $25.5B (fiscal year ended Dec 2025). CEG's net margin was 9.1% and SO's 14.7%. Both file with the SEC under the same industry code, SIC 4911 (Electric Services). Each figure is the annual amount tagged in the company's own SEC XBRL filing; market value depends on live prices, which this page does not publish.
Which is better, CEG or SO?
There is no context-free winner. Compare the operating exposures, filing evidence, valuation, balance sheet, and risks against the specific thesis you are testing. This page deliberately does not turn a static profile into a buy or sell recommendation.
Does this CEG vs SO comparison include live prices?
No. Yield Theory does not republish unlicensed real-time market data. The financial figures on this page are the audited annual numbers Constellation Energy Corporation and The Southern Company tagged in their SEC XBRL filings. Use a regulated broker or licensed quote provider for current prices and valuation multiples.
Where does the company information come from?
Company classifications, fiscal year-ends, and filing links come from the SEC EDGAR submissions API snapshot refreshed 2026-10-03. Business summaries and research themes are maintained by Yield Theory.
Data snapshot: SEC EDGAR submissions API, refreshed 2026-10-03. Independent educational research; not investment advice.
Which business differences matter to the investment thesis?
CEG vs SO compares reported results. The reports below show how we connect operating evidence to an investment thesis, its assumptions, catalysts, and risks. $39/month or $249/year.
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