Sometimes, beating expectations isn't enough. Shares of NuScale Power Corp. (SMR) slipped in Thursday's extended session even after the company reported fourth-quarter results that came in better than analysts had feared.

Here's the headline number: NuScale reported a quarterly loss of eight cents per share. That might not sound like a win, but the market was bracing for a loss of 13 cents, according to market data. Quarterly revenue landed at $1.81 million.

The full-year picture, however, shows some moving parts. Revenue for the year came in at $31.5 million, down from $37 million the previous year. The company says that drop was "primarily due to a reduction in revenue recognized from the RoPower technology license agreement executed in 2024." In simpler terms, the timing of how they book revenue from that big deal changed, which affected the year-over-year comparison.

Another big shift was on the cost side. NuScale's cost of sales ballooned to $20 million for the year, up sharply from $4.9 million the year before. The company pins this increase on "the engineering services required by Fluor under their FEED Phase 2 contract with RoPower." It's worth noting that the licensing revenue from that technology agreement itself carries no cost of sales—the costs are tied to the specific engineering work.

Despite the mixed financials, CEO John Hopkins struck an optimistic note. "For NuScale, 2025 was a breakthrough year, in which we further solidified our position as the SMR industry's first mover," he said.

Investors, however, seemed focused on the immediate reaction. After the report, NuScale stock fell 3.23% to $12.90 in after-hours trading. It's a reminder that in the markets, sometimes the "why" behind the numbers matters just as much as the numbers themselves.