OKLO, XE, SMR, NNE, UEC Stocks Tumble On Thursday: AI Made Nuclear Stocks Market Darlings – Now Investors Want Proof

• The decline adds to an already difficult year for nuclear energy stocks, which have dipped significantly since the start of 2026.
• Truist analyst Christopher Souther recently noted that investors are increasingly looking for evidence that these companies can successfully build, license and deploy reactors on schedule. 
• Standard Nuclear (STDN), a Tennessee-based manufacturer of uranium fuel pellets, had a tepid debut on Wednesday, further highlighting skepticism in the industry. 

Nuclear stocks tumbled Thursday as investors continued to rotate out of some of Wall Street's most expensive AI-linked trades, signaling a shift from enthusiasm about future power demand to scrutiny of whether advanced reactor companies can actually deliver on ambitious timelines.

Oklo Inc. (OKLO), X-Energy Inc. (XE), NuScale Power Corp. (SMR), Nano Nuclear Energy Inc. (NNE), and Uranium Energy Corp. (UEC) came under pressure, with the stocks losing between 8% and 9%. 

The decline adds to an already difficult year for the nuclear energy stocks that have dipped significantly since the start of 2026 despite continued enthusiasm for the nuclear space in the long-term.

Nuclear Stocks: Wall Street Wants More Than AI Optimism

Recently, Truist analyst Christopher Souther initiated coverage of Oklo, NuScale Power and Nano Nuclear, assigning ‘Hold’ ratings to all three companies, as per TheFly. 

The analyst noted that the sector's "first-of-a-kind projects" are now moving from concept to execution. Although customer demand and policy support remain favorable, investors are increasingly looking for evidence that these companies can successfully build, license and deploy reactors on schedule, as per the analyst. 

The comments highlight a significant shift that is underway in the market. Many of the nuclear stocks above surged in 2025 amid growing AI-driven power demand and an increasingly supportive policy backdrop in the U.S.

The VanEck Uranium and Nuclear ETF (NLR), which tracks global companies in uranium mining and nuclear power generation, surged over 50% in 2025, but has lost about 15% of its value so far in 2026. 

However, sentiment has soured in recent months, with markets questioning high valuations of the companies that are still years away from commercial-scale operations. 

For instance, XE stock traded at a trailing enterprise value to sales multiple of 48.4x, while that number was a whopping 91.2x for SMR. 

AI Rout Deepens Nuclear Selloff

Meanwhile, a rotation out of the AI sector has deepened the rout in nuclear stocks. 

"There's this sense that we all know AI is going to change the world in so many ways. We all know that space is big, defense is big, nuclear energy is big. All these things are big. Therefore, more and more money goes into these things and they just keep getting marked up," Everett Randle, General Partner at Benchmark, said to Technology Business Programming Network (TBPN) on Thursday. 

"The last time I felt like investors had this much of a sense of inevitability saying, 'Yes, it's expensive, it's going to get marked up in six months so therefore we should do it.' was the summer and fall of 2021. We all know how that ended up," he added. 

Randle was referring to the boom of late 2021, when investors piled into expensive growth stocks before rising interest rates triggered a sharp market correction.

Fresh Nuclear IPO Highlights Industry Concerns

Standard Nuclear (STDN), a Tennessee-based manufacturer of uranium fuel pellets, debuted on Wednesday, raising $150 million at a valuation of about $2 billion. 

However, shares of the company opened below the offering price of $15 and are currently trading about 16.7% lower.

For context, Standard Nuclear, which acquired assets from a bankrupt nuclear firm in 2024, is already generating revenue and has been selected as a partner in the U.S. Department of Energy's nuclear acceleration program. However, its long-term growth remains tied to the success of advanced reactor developers such as Oklo, X-Energy, and other nuclear companies, according to a report from Barron’s. 

Cathie Wood Doubles Down On Nuclear Stocks

However, not everyone is steering clear of these names. Cathie Wood’s Ark Investment Management has doubled down on nuclear companies in recent weeks amidst their decline. The asset management firm has picked up significant shares in X-Energy and Oklo. 

Even on Thursday, the firm purchased 507,347 XE shares for about $7.64 million, according to the company’s trade notifications. 

OKLO, XE, SMR, NNE, UEC Stocks: What Does Retail Think?

On Stocktwits, retail sentiment around OKLO and UEC stocks was ‘neutral,’ while it was ‘bearish’ for SMR and XE stocks. NNE stock was in the ‘bullish’ territory at the time of writing. 

One user said that days like these when stocks fall should remind traders of “fear & greed." The user added that “Volatility is chaos and anarchy rules, but solvency is survival and cash is king.”

Another user said, “$OKLO $SMR another garbage day, bulls should sell before the classic -99% in fske companies or pennystocks.”

A third user on SMR said, “the entire sector getting smashed and all gaps filled.”

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