When you look at the stock performance of nuclear energy company Oklo (OKLO 5.34%), it's hard not to feel your eyes burn.
At the time of writing, this stock is up 1,945% year over year. Year to date, it's up 518%, with a recent single-day pop of almost 29% on Sept. 19, 2025.
That's a lot for an energy stock, especially for a company that isn't generating meaningful revenue. Does Oklo have some kind of magic, or is the company's almost $20 billion market cap a mirage?
Image source: Getty Images.
Why Oklo has climbed so high -- and what's stopping it from soaring
Oklo is designing an advanced "microreactor." These reactors (called "Aurora" powerhouses) are being engineered to run on both high-assay low-enriched uranium (HALEU) and recycled nuclear fuel, a one-two punch that should make them not only more efficient but less wasteful than traditional nuclear reactors.
Their compact and modular design means that they could be assembled near AI data center campuses and other remote areas, like military bases and mining sites.
Oklo has also expanded into radioisotope production with its acquisition of Atomic Alchemy. The goal is to produce medical isotopes domestically to "address urgent supply shortages." For a pre-revenue company like Oklo, it could mean generating revenue before its powerhouses are online.
And therein lies the kicker: Oklo's Aurora powerhouses don't have regulatory approval, and Oklo hasn't built a commercially operable full-scale Aurora reactor yet. It's also bleeding cash (an expected $65 million to $80 million cash burn for 2025) and may not generate revenue on its powerhouses until decade's end.
Lucky for Oklo, the White House is bullish on nuclear energy. In early summer, President Donald Trump signed executive orders furthering the development of advanced nuclear reactors. And recently, the U.S. and U.K. governments jointly signed an initiative to accelerate safety checks on small modular reactors and microreactors -- Oklo's bread and butter.
It's worth pointing out that NuScale Power, an SMR designer, also surged on the same news.
For now, Oklo is a speculative play on clean energy. Less aggressive investors may want to consider a nuclear energy exchange-traded fund (ETF) instead.
