Cathie Wood Just Poured Millions Into 2 Nuclear Stocks -- and Neither Was NuScale Power
Cathie Wood's Ark Invest ETFs purchased shares of X-Energy (XE) and Oklo, investing approximately $5.1 million and $4.1 million respectively. X-Energy's shares were added to ARKK, ARKQ, and ARKX, while Oklo was added to ARKQ. Both companies are involved in nuclear energy, with X-Energy focusing on SMR design and nuclear fuel production, and Oklo developing nuclear fuel recycling and isotope production.
How this was made

The 30-second read
Why it matters
The disclosed purchases provide fresh, primary information about institutional demand for these micro‑caps, which could influence short‑term price dynamics.
Market read
First‑time fund allocations to X‑Energy and Oklo may spark modest buying interest and short‑term price support in the niche nuclear sector.
What to watch
Regulatory timelines and commercial rollout of SMR technology remain uncertain, which could limit upside despite fund interest.
Background
Cathie Wood’s Ark Invest funds have recently added positions in two small‑cap nuclear companies, X‑Energy and Oklo, after previously avoiding NuScale Power.
Ticker impact
Ark Invest ETFs bought roughly $5.1 M of X‑Energy shares on Oct 22, marking the first disclosed fund purchase of the stock.
likely modest upward pressure as the market prices in the new institutional demand
The purchase size is small relative to market float, but Ark’s endorsement often triggers interest from other investors.
Ark Invest ETFs purchased about $4.1 M of Oklo shares on Oct 22, representing the first reported fund allocation to the company.
likely modest upside as investors view the purchase as validation of Oklo’s nuclear‑fuel strategy
Oklo is a micro‑cap; fund buying can move the stock but the impact is limited by overall liquidity.
Market effects
Highlights growing investor interest in nuclear SMR and fuel companies, potentially benefitting the broader clean‑energy sector.
U.S. small‑cap nuclear stocks may see modest inflows from other funds tracking Ark’s moves.
Limited; primarily relevant to U.S. investors focused on niche nuclear technology plays.
Counterpoint
The purchases are small relative to market cap; investors should weigh execution risk of SMR projects before following the fund.
Key entities
- companyX‑Energy
SMR designer and nuclear fuel producer (NASDAQ: XE).
- companyOklo
Nuclear fuel recycling and isotope production firm (NASDAQ: OKLO).
- investment_firmArk Invest
Cathie Wood’s active management firm that allocated capital to the two nuclear stocks.


