Oklo (NYSE: OKLO) dropped roughly 6% to close at $41 on Tuesday, while NuScale Power (NYSE: SMR) slid a similar 6% to $9, and Constellation Energy (NASDAQ: CEG) fell about 4% to $267.
The sell-off across nuclear names was driven largely by fresh doubts about AI capital expenditure, which has underpinned much of the sector’s recent investor enthusiasm.
Anthropic disclosed that its annualized revenue run rate reached $65 billion at the end of July, and Reuters reported the company is guiding IPO investors toward 2028 revenue of $190 billion to $200 billion.
Both figures landed well below expectations circulating in Silicon Valley, where investors including Gavin Baker had cited an ARR closer to $80 billion and a projected exit valuation of $400 billion to $500 billion next year.
That disappointment compounded a Wall Street Journal analysis revealing nine top tech companies carry roughly $3 trillion in off-balance-sheet commitments tied largely to AI, growing faster than traditional capex of roughly $600 billion over the past year.
Long-term power purchase agreements, exactly the type of forward liability the Journal was counting, place nuclear developers directly in the line of fire as investors question the durability of hyperscaler spending.
Rising Treasury yields added further pressure, with the 30-year bond printing a 19-year high at 5.31% and the 10-year reaching 4.68%, a direct blow to the net present value of capital-intensive, long-duration nuclear projects.
The intraday market picture was telling, with technology finishing as the worst-performing sector while healthcare, consumer defensives, utilities, and energy all traded higher, exposing the AI-derivative status of these nuclear names.
Constellation stands apart from its peers in one key respect, operating a producing fleet with real cash flow, having delivered Q2 adjusted earnings per share of $2.55 against a consensus of $2.33 on revenue of $7.5 billion, with management raising full-year 2026 adjusted EPS guidance to between $11.50 and $12.50.
CEO Joe Dominguez stated on the Q1 earnings call that “demand for additional compute, and by extension, additional power, has not slowed from hyperscaler customers,” adding that projected 2026 spending was “nearly 75% higher than last year and continue to be revised upward.”
Oklo and NuScale remain pre-revenue companies with commercial power generation still years away, making them far more exposed to shifts in sentiment around AI infrastructure investment.
Tuesday’s declines interrupted what had been a meaningful recovery, with Oklo up about 7% over the prior month, Constellation up roughly 10%, and NuScale surging around 19% in the same period.
Year to date, however, all three remain sharply lower, with Oklo down 39%, Constellation off 21%, NuScale down 35%, and NuScale registering a decline of roughly 74% over the past twelve months.
