Shares of nuclear power startup Oklo (OKLO 1.75%) have skyrocketed in September, with shares gaining about 50% in price during the past month alone.
At more than $100 a share, the stock is now up more than 12-fold from its year-ago price. Have investors missed the boat, or is there still time to cash in on this red-hot growth stock?
A startup that's just starting up
Oklo is one of a number of nuclear energy startups exploring small modular reactor (SMR) technology. Unlike existing nuclear plants, which have footprints of about one square mile, SMRs can be housed in a facility about the size of a large warehouse.
In fact, on Sept. 22, Oklo held a huge groundbreaking ceremony near Idaho Falls, Idaho, for just such a facility. This will be the first Aurora power plant, an SMR-powered electrical generation plant. Once the power plant is constructed, it will house a sodium-cooled fast reactor SMR, which is theoretically more efficient and can be powered by spent fuel from existing reactors in addition to the standard enriched uranium fuel.

Image source: Getty Images.
The key word here -- and why Oklo is a speculative stock -- is "theoretically."
Friends in high places
This will be Oklo's first attempt at creating a working prototype of its SMR, so it's in a similar situation as a biotech startup with a drug that's about to start clinical trials: if the drug works with no unforeseen problems, the company is likely to get regulatory approval to start selling its drug and its stock price will jump. If the drug doesn't work as well as expected, or causes unforeseen serious side effects, the drug may not be approved and the stock will crash. In other words, Oklo's not for risk-averse investors.
One big difference, though, is that while drug trials usually last five years or more, Oklo's nuclear test power project is on a much faster timeline. Oklo is participating in the Reactor Pilot Program run by the U.S. Department of Energy (DoE). The program's goal is to demonstrate criticality in three test reactors by July 2026: less than a year from now.
A lot of influential people want to see Oklo's project succeed. Speakers at the groundbreaking ceremony included Interior Secretary Doug Burgum, U.S. Environmental Protection Agency (EPA) administrator Lee Zeldin, the governors of both Idaho and Utah, U.S. Nuclear Regulatory Commission (NRC) commissioner Bradley Crowell, and members of the U.S. Senate.
Support from these key players -- many representing agencies that will need to approve the project or some portion thereof -- doesn't guarantee that the technology will work as planned, but it certainly can't hurt.
How high can it go?
At this stage, it's difficult to value Oklo as a business. The company has no current sales or earnings to speak of, and won't have any until it begins to commercialize its SMRs and sell the power they generate. But what would Oklo be worth at that point?
Oklo's SMRs are expected to generate as much as 75 megawatts (MW) of electricity each -- compared to about 1,000 MW for a standard nuclear power plant -- but their actual cost and generation capacity under real-world conditions is unknown. However, Oklo says it has a current "customer pipeline" representing 14 gigawatts (GW) of total generation capacity (although it's unclear how firm these customer commitments are). But for the sake of argument, let's use that number. What is 14 GW of generation capacity actually worth?
It's tough to find an apples-to-apples comparison, since many energy companies provide electricity transmission and distribution or natural gas services alongside their electricity generation, but PPL Corporation (PPL -0.42%) and WEC Energy Group (WEC -0.21%) each have generation capacity of between 7.5 and 8.5 GW (in addition to providing other services) and market caps of $27 billion and $37 billion, respectively. This suggests that Oklo would be worth much more than its current $17 billion market cap if its technology performs as expected.
But if Oklo's SMRs work as planned, an excited market is likely to bid its shares up even further, meaning that there's still plenty of potential upside for Oklo's stock, even at its current valuation. Unfortunately for new investors, though, there's not as much upside as there was a month ago. But if you can stomach the risk, it doesn't look too late to buy in.