So, you're a Bitcoin miner. The price of Bitcoin goes up, you make more money. Simple, right? Well, not exactly, as the latest earnings from Riot Platforms, Inc. (RIOT) show. The company's shares slipped in Monday's extended session after it reported its fourth-quarter numbers, a reminder that in the mining game, costs matter just as much as the crypto price on the screen.

Here’s the headline from the quarter: Riot posted a loss of $2.03 per share. The revenue number came in at $152.83 million. That’s the kind of math that tends to make investors a bit cautious, even in a sector known for its volatility.

But to understand the full picture, you have to zoom out to the full year. Riot is calling 2025 a "watershed year," and by the raw numbers, it's hard to argue. Total revenue hit $647.4 million, a big jump from $376.7 million in 2024. The engine behind that growth? Bitcoin. Mining revenue specifically surged to $576.3 million from $321 million the year before. The company also produced more of the digital asset—5,686 Bitcoin versus 4,828.

But here’s the catch, and it’s a crucial one for any mining operation: the cost of doing business went up, too. The average cost to mine a single Bitcoin (before accounting for depreciation) ballooned to $49,645 for the year. That’s up sharply from $32,216 per Bitcoin in 2024. So yes, revenue was way up, but so was the expense of generating that revenue. It’s a classic story of scaling an operation—it doesn't always get cheaper per unit as you grow, especially when the global network hash rate you're competing against is also increasing.

The other revenue stream, engineering, also grew healthily to $64.7 million from $38.5 million.

So why the "watershed" talk from CEO Jason Les? It’s less about the pure mining metrics and more about a strategic pivot. "By unlocking our large, nearly two-gigawatt power portfolio for high-demand data center infrastructure, we are driving significant shareholder value," Les said. In plain English, Riot is looking beyond just plugging in miners. It sees its massive power capacity—the lifeblood of mining—as a valuable asset that can be leased or used for other compute-intensive data center work, like AI. It’s a bet on turning a key operational input into a diversified revenue stream.

Investors in the after-hours market seemed to be focusing more on the quarterly loss than the annual transformation story. According to market data, Riot stock was down 1.28% to $16.22. The trade-off is clear: the company is investing in a future that looks different from its past, but that future comes with present-day costs that are weighing on the bottom line.