Oklo (NYSE: OKLO) has reached a significant milestone in small modular reactor development, announcing that its Groves Isotope Test Reactor in Texas has achieved nuclear criticality.
Criticality occurs when a nuclear chain reaction becomes self-sustaining enough to produce a steady and continuous release of energy, marking a foundational step toward commercial viability.
The achievement makes Oklo’s Texas reactor the fifth small modular reactor to reach this level of capability under a U.S. Energy Department pilot program.
That federal program was specifically designed to expedite development of new nuclear technology and demonstrate its real-world viability to investors and policymakers alike.
Small reactors developed by Aalo Atomics, Deployable Energy, Antares Nuclear Inc., and Valar Atomics Inc. had previously achieved the same criticality milestone before Oklo.
Small modular reactors, or SMRs, represent a next-generation approach to nuclear power, offering more flexible construction, rapid deployment, lower costs, and enhanced safety compared to traditional plants.
Unlike conventional nuclear facilities, which require vast land and decades-long construction timelines, SMRs are designed to be deployed faster and with greater geographic flexibility.
Despite the breakthrough, SMR technology is not yet commercially available in the United States, and significant regulatory and engineering hurdles still stand between criticality and full commercial operation.
Oklo shares responded positively to the news, rising 4.3% to $44.86 in pre-market trading in New York following the August 6 announcement.
The development carries meaningful implications for exchange-traded funds with significant exposure to Oklo stock, particularly two funds tracking the nuclear energy sector.
The VanEck Uranium and Nuclear ETF holds approximately 4.4% of its assets in Oklo, giving its investors direct exposure to the company’s progress on SMR development.
The Global X Uranium ETF carries an even larger position, with Oklo representing roughly 6.2% of its portfolio, amplifying the potential impact of any sustained rally in Oklo shares.
Both funds stand to benefit if Oklo continues to advance its SMR program and moves closer to eventual commercial deployment of its reactor technology.
The broader nuclear energy sector has attracted growing investor interest as governments and corporations seek reliable, low-carbon baseload power to meet surging electricity demand driven by artificial intelligence infrastructure and data centers.
