Nuclear Stocks Plunge Tuesday: Oklo Down 5%, Constellation Energy Down 4%, NuScale Down 5%

Nuclear names sold off hard into Tuesday’s close. Oklo (NYSE:OKLO | OKLO Price Prediction) finished down roughly 6% at $41, Constellation Energy (NASDAQ:CEG) fell about 4% to $267, and NuScale Power (NYSE:SMR) slid roughly 6% to $9.

While companies sold off across the space throughout the day, the real storyline was a sell-off across AI stocks. Let’s dive in.

AI Capex Doubts Meet a 19-Year High in Long Rates

Anthropic told investors its annualized revenue run rate reached $65 billion at the end of July, and Reuters reported the company is guiding IPO investors to 2028 revenue of $190 billion to $200 billion. Both figures came in below the numbers circulating in Silicon Valley, where investors like Gavin Baker had cited an ARR closer to $80 billion and an exit next year of $400 billion to $500 billion.

That reset landed on top of a Wall Street Journal analysis showing nine top tech companies carry roughly $3 trillion of off-balance-sheet commitments tied largely to AI, a figure growing faster than traditional capex of roughly $600 billion over the past year. Long-term power purchase agreements are exactly the kind of forward liability the WSJ was counting, which puts nuclear developers squarely in the crosshairs of the durability debate.

Rates piled on. The 30-year Treasury printed a 19-year high today, with the long bond at 5.31% and the 10-year at 4.68%. Nuclear projects are among the most capital-intensive, longest-duration investments in energy, so a higher discount rate is a direct hit to net present value, particularly for pre-revenue developers.

Utilities Green, AI-Linked Power Names Red

The intraday tape flagged the split clearly.

Technology was the worst-performing sector while healthcare, consumer defensive, utilities and energy traded higher. Utilities broadly caught a bid, yet these AI-linked power names fell. The market is treating Oklo, NuScale, and to a lesser extent, Constellation, as derivatives of hyperscaler capex, not as classic utilities. (For readers thinking about how to position for the restart itself rather than the sentiment swings, we mapped five ways to play it, utilities and fuel included, in a free report: here.)

Constellation deserves separate framing. It is an operating fleet with real cash flow backed by earnings. Q2 delivered adjusted EPS of $2.55 versus the $2.33 consensus on revenue of $7.5 billion, and management raised FY26 adjusted EPS guidance to $11.50 to $12.50. CEO Joe Dominguez said on the Q1 call that “demand for additional compute, and by extension, additional power, has not slowed from hyperscaler customers” and that projected 2026 spending was “nearly 75% higher than last year and continue to be revised upward.”

Oklo and NuScale, by contrast, remain pre-revenue bets with commercial power still years out.

Today interrupts a recovery within a broader rally. Over the past month, Oklo is up about 7%, Constellation up roughly 10%, and NuScale up around 19%. Year to date, though, all three remain deep in the red: Oklo -39%, Constellation -21%, and NuScale -35%. NuScale is down roughly 74% over the past year.

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