Oklo Inc. (NYSE: OKLO) has demonstrated it can deliver on its construction promises, announcing that its Groves Isotope Test Reactor in Lockhart, Texas, achieved first criticality on August 6, 2026.
The milestone, defined as a controlled and self-sustaining nuclear chain reaction, was reached less than a year after the project broke ground on a previously undeveloped site.
Oklo says the Groves reactor is the first project under the U.S. Department of Energy’s Reactor Pilot Program to reach criticality on private land from a greenfield site.
The company also claims Groves may be the fastest privately funded, privately sited reactor build in American history, a bold assertion that management tied to an under-11-month construction timeline.
CEO Jacob DeWitte called it “an incredible milestone for our team,” noting that Oklo handled civil excavation and construction itself and manufactured or procured every component, including fuel, in-house.
The Groves reactor is designed to anchor Oklo’s isotope business, supplying materials for healthcare, industry, research, space, and national security applications, with revenue expected to begin in the first half of 2027 from a commercial Idaho radiochemistry lab.
Management believes the engineering practices, training programs, and commissioning experience gained from Groves will reduce execution risk across the company’s future isotope, powerhouse, and fuel cycle projects.
Oklo reported a net loss of $81.6 million for the quarter and an operating loss of $124.2 million, reflecting the reality that the company remains unprofitable as it builds toward commercial scale.
The company raised its 2026 operating cash flow guidance to between $120 million and $150 million, up from an earlier range of $80 million to $100 million, while also lifting capital expenditure guidance to between $400 million and $500 million.
Oklo’s balance sheet appears well-positioned to absorb those costs, with $3 billion in cash and marketable securities on hand after the company raised $1.9 billion in 2026 through its at-the-market programs.
Site excavation at the Aurora-INL project is described as nearly complete, and a Kiewit memorandum of understanding is advancing the 1.2-gigawatt Ohio Power Campus that will supply Meta with electricity.
The Aurora-INL project, which would validate Oklo’s commercial powerhouse platform, is not targeted to start up until 2028, and the first phase of the Aurora-Ohio powerhouse is not expected until early 2030.
Short interest in the stock currently sits at 2.89% of the float, representing real but not overwhelming skepticism, while the hedge fund count tied to the stock held flat at 36 funds quarter-over-quarter.
Shares surged more than 10% on August 7, the day after the criticality announcement coincided with Oklo’s earnings report, reflecting investor enthusiasm for a company that delivered a concrete operational milestone ahead of its commercial power ambitions.
