Oklo Inc. (OKLO) shares had a rough Monday, giving back earlier gains despite getting an upgrade from Seaport Global. Analyst Jeff Campbell bumped the nuclear startup from Neutral to Buy and slapped a $150 price target on it, but investors weren't exactly rushing to celebrate.

Why the Upgrade?

Campbell's bullish turn centers on two things: solid execution and a smart fuel choice. After digging through Oklo's third-quarter earnings, he came away impressed with the company's progress across multiple fronts.

"OKLO's 3Q25 call provided a wealth of information about its multivariate progress in executing its business plan," Campbell wrote. "In this quarter, we focus on those items that strike us as most impactful and thought-provoking with a focus on Pu-239 as fuel."

That $150 price target? It's pegged to 15 times the firm's 2032 EBITDA estimate of $1.59 billion, which suggests Campbell sees real revenue potential down the road.

The Plutonium Angle

Here's where things get interesting. Campbell views the shift toward plutonium-239 as more effective than high-assay low-enriched uranium (HALEU). A recent White House order to release surplus plutonium-239—previously headed for disposal—lets Aurora return to its design roots from the Integral Fast Reactor era at Idaho National Laboratory.

Oklo's third-quarter update showed real momentum: construction is moving forward at the Atomic Alchemy pilot plant in Texas, the company added a third reactor under the DOE's pilot program for plutonium testing, and it's developing the INL Aurora site under DOE authorization with plans for eventual dual DOE/NRC approval.

Then there's the Tennessee fuel recycling facility—the first stage of a $1.68 billion Advanced Fuel Center. That's not small potatoes.

Despite all this positive news, Oklo shares closed down 2.52% at $102.03 on Monday. Sometimes the market needs time to digest good news, or maybe traders were just taking profits after an earlier pop.