Key points
- Oklo (OKLO) rose 14.8% Friday after its Groves reactor reached first criticality and the company posted its first quarterly revenue, $1.21 million.
- X-Energy (XE), Centrus Energy (LEU), enCore Energy (EU) and NANO Nuclear Energy (NNE) all gained more than 7%; Cameco (CCJ) rose 4% and Constellation Energy (CEG) rose 3.4%.
- Vistra (VST) was the one name in the group to fall, down 0.5%, even as the rest of the nuclear and uranium trade rallied.
On August 7, Oklo (OKLO) announced that its Groves test reactor site in Lockhart, Texas, reached criticality on August 5 at 9:19 p.m. ET. That means the reactor achieved a controlled, self-sustaining nuclear chain reaction. Oklo said Groves is the first reactor under the Department of Energy's Reactor Pilot Program to reach criticality on private land. It's also the fastest privately funded, privately sited reactor build the company is aware of, achieved less than a year after groundbreaking. Construction took 229 days. Chief executive Jacob DeWitte said in the earnings release: "Groves represents the fastest transition that we are aware of from greenfield to criticality for a full-scale, privately funded and privately sited reactor in history."
After that news, every nuclear and uranium stock we track moved higher Friday, except one. Oklo led the group, up 14.8% to $48.43. The company also reported its first quarter of revenue since going public.
Groves is a low-power isotope reactor, not one of Oklo's commercial Aurora power plants. Those are still years out: the first Aurora unit, at Idaho National Laboratory, is targeted for late 2027 or early 2028, with a second plant, Aurora-Ohio, meant to supply Meta's data centers, following in early 2030.
Oklo also released its second-quarter results the same morning. Revenue was $1.21 million, the first quarter the company has ever reported any revenue at all. A year earlier it was zero. The net loss widened to $48.5 million from $24.7 million a year earlier, as research and development spending rose to $39.5 million on the Groves build. Oklo still ended the quarter with $3 billion in cash and marketable securities.
How the rest of the group did
| Company | Friday move | Last price |
|---|---|---|
| Oklo (OKLO) | +14.8% | $48.43 |
| Centrus Energy (LEU) | +7.5% | $191.30 |
| enCore Energy (EU) | +7.8% | $1.24 |
| NANO Nuclear Energy (NNE) | +7.0% | $18.85 |
| X-Energy (XE) | +8.9% | $22.68 |
| Cameco (CCJ) | +4.0% | $97.40 |
| Constellation Energy (CEG) | +3.4% | $269.98 |
| NuScale Power (SMR) | +3.8% | $9.83 |
| BWX Technologies (BWXT) | +1.9% | $169.92 |
| Vistra (VST) | -0.5% | $140.69 |
Constellation Energy, the largest owner of nuclear generation in the United States, carried its own catalyst into Friday. Constellation reported second-quarter adjusted operating earnings of $2.55 a share on Thursday, beating the $2.36 Wall Street expected, and raised full-year guidance to a range of $11.50 to $12.50 a share, a report we previewed here. "Strong results, an increase in guidance, positive regulatory developments, good progress on strategic transactions. Our team delivered," chairman, president and chief executive Joe Dominguez said on the earnings call. Constellation separately signed about 920 megawatts of new long-term power purchase agreements tied to nuclear output. The Nuclear Regulatory Commission approved a new fuel licensing request for the Crane Clean Energy Center, keeping its planned restart on track for the second half of 2027.
Vistra, a broader power generator whose nuclear fleet is a smaller share of its business than Constellation's, was the exception to Friday's move. It closed down 0.5% at $140.69.
The move builds on gains already in place this summer. We covered Oklo and X-Energy jumping together in July on a separate Trump administration nuclear-for-AI announcement, and wrote about the sector's broader setup in AI's power problem. Uranium's spot price was $86.30 a pound as of August 5, according to data tracked by Yahoo Finance, with utilities' long-term contract price running well above that, near $94 a pound as of June, a gap that has kept uranium miners and enrichers like Centrus and enCore bid up even as spot has drifted sideways.
Oklo's earnings call also touched on the isotope side of the business Groves is meant to serve. DeWitte told analysts: "We are building one integrated nuclear technology platform across power, fuel, and isotopes." Groves is designed to produce medical and industrial isotopes once it moves past low-power testing, a separate revenue line from the Aurora power plants still years from operating.
