Shares of Oklo (NYSE: OKLO) tumbled 27% in the first half of 2026, with nuclear energy enthusiasm cooling after a remarkable run the prior year.
According to data from S&P Global Market Intelligence, the stock remains down 71% from the highs it set in 2025, despite a five-year gain of 386%.
Oklo is a nuclear reactor startup developing a design called the Aurora Powerhouse, intended for direct electricity generation at data centers and industrial facilities.
The company’s goal is to keep electricity-intensive operations from placing additional burden on the grid that serves homes and everyday consumers.
A central challenge for Oklo is that its Aurora Powerhouse reactor design has not yet received approval from the Nuclear Regulatory Commission in the United States.
That regulatory gap means the company is likely still years away from building and delivering operational reactors to paying clients.
While Oklo is pursuing radioisotope production and nuclear fuel recycling in the meantime, those ventures represent much smaller opportunities compared to actually constructing and operating full-scale reactors.
With no revenue coming in, the company has been burning through cash at an accelerating rate, posting negative free cash flow of $154 million over the last twelve months, the worst in its history.
To shore up its balance sheet, Oklo has repeatedly sold shares of common stock, a dilutive move that has more than doubled shares outstanding over the past few years and placed consistent pressure on the share price.
The broader AI-driven excitement that propelled nuclear energy stocks higher throughout 2025 has also begun to cool, dragging down names like Oklo as investor sentiment shifts.
On the positive side, Oklo held over $2 billion in cash and equivalents on its balance sheet at the end of the first quarter of 2026, providing meaningful runway as it pursues regulatory approval.
That cash cushion should allow the company to continue operations for several years without immediately needing to tap capital markets again.
However, the nuclear energy sector has long been known for slow-moving regulatory processes and high barriers to entry, making life difficult for startups attempting to bring new products to market quickly.
With a market capitalisation still sitting at $8.5 billion and zero revenue, Oklo’s valuation remains a significant concern for investors considering whether to buy the recent dip.
