Oklo (NYSE: OKLO) has lost more than 60% of its stock value in 2026, a brutal decline that stands in sharp contrast to genuine technical progress the company has made this year.

The VanEck Uranium and Nuclear ETF (NLR) has also taken a significant hit, shedding roughly 25% of its value as broader sentiment toward nuclear energy investments has shifted dramatically.

Wall Street’s enthusiasm for nuclear power, once a rallying force that drove speculative investment across the sector, has cooled into something closer to skepticism and outright doubt.

The reversal reflects a broader reassessment of AI infrastructure spending, which had previously been one of the most powerful tailwinds behind nuclear energy stocks like Oklo.

Investors are now questioning whether the enormous capital being directed into AI infrastructure will generate the returns that were once assumed, and that uncertainty has weighed heavily on companies dependent on large-scale energy contracts.

Oklo’s business model is tightly linked to the prospect of sustained, large-scale infrastructure investment, making the stock particularly exposed to shifts in confidence around AI-driven power demand.

Compounding the investor anxiety is the fact that Oklo has not yet received regulatory approval for its Aurora powerhouse, leaving the company without a licensed commercial product despite years of development work.

Against that backdrop of regulatory uncertainty and shifting market sentiment, the company did achieve a significant scientific milestone in August, when its Groves test reactor in Texas reached first criticality.

First criticality is the point at which a nuclear reactor sustains a chain reaction for the first time, a foundational step that confirms the reactor has been successfully built and is capable of operating.

That achievement marks Oklo as a company that has moved beyond pure concept and proposal, demonstrating real-world nuclear capability at a time when most small reactor developers remain years away from similar milestones.

The gap between the stock’s performance and the company’s technical progress illustrates a disconnect that investors focused solely on share price movements may be overlooking entirely.

Whether that disconnect represents a buying opportunity or simply an early-stage company navigating a difficult market remains a question that Wall Street has not yet answered with any consistency.