I've been watching these two nuclear fission stocks pretty closely, and there's something interesting happening in the market right now that's worth unpacking.

Back in July, NuScale Power looked like the obvious winner in the small modular reactor space. Better revenue, more reasonable valuation — pretty straightforward. But then something wild happened. NuScale's stock tanked nearly 80% while Oklo barely dropped 20%. That kind of divergence doesn't happen for no reason, so let me break down what's actually going on here.

Both companies are trying to revolutionize nuclear energy, but they're taking different approaches. NuScale builds SMRs — small modular reactors that fit in compact vessels, only 65 feet tall and nine feet wide. They're prefabricated and modular, which cuts down on construction time and costs. The company actually holds the only Standard Design Approval from the NRC, and their 77 MWe design is already being used for Romania's RoPower project. They also landed a massive TVA deal to deploy up to six gigawatts across seven states. That's real validation.

Oklo's going even smaller with microreactors. Their Aurora unit generates just 1.5 MWe on its own, but you can chain them together for 15 to 100 MWe per deployment. The real advantage? They use metallic uranium fuel that's denser and cheaper to produce, plus they recycle fuel in a closed loop so they run about a decade without refueling. Compare that to conventional reactors needing refueling every two years. Oklo broke ground on their first Idaho project last year and they're working with Siemens Energy on turbine systems.

Here's where the valuation story gets interesting. Oklo trades at over 600 times its projected 2027 sales with a market cap around $9.7 billion. NuScale sits at roughly 19 times its 2027 sales with a $3.9 billion market cap. On paper, NuScale looks way more reasonably priced. But there's a catch — timing.

NuScale won't see actual reactor deployments until the early 2030s. Between now and then, they're basically running on FEED studies, converting MOUs into contracts, and licensing deals. Analysts expect revenue to jump from $31 million to $287 million by 2028, but that's still peanuts compared to when reactors actually come online. Oklo, though, is supposed to deploy their first Idaho reactors in late 2027 and generate $16 million in revenue that year. That's a near-term catalyst the market is clearly pricing in.

The market seems to be betting that those near-term catalysts matter more than long-term potential right now. Oklo has visibility into 2027 deployments. NuScale's biggest growth story is still years away. In a choppy market, investors are favoring the company with nearer-term momentum, even if the valuation looks stretched.

Neither company will disrupt the nuclear energy market overnight, but if you're looking at nuclear fission stocks as a long-term play, both could eventually deliver massive returns. The question is whether you want to wait for NuScale's 2030s catalysts or ride Oklo's near-term deployments. Right now, the market's clearly chosen.