Miners are selling bitcoin and building data centres for AI

The second-quarter 2026 numbers show the largest bitcoin miners rebuilding their business model. MARA Holdings reported revenue of 174.9 million dollars (roughly €153.0 million), down 27 per cent year on year, and a net loss of 611.3 million dollars (roughly €534.9 million), or 1.60 dollars per diluted share. CleanSpark, which runs a split financial year, reported 138.0 million dollars (roughly €120.8 million) for the quarter to the end of June, a fall of 30.5 per cent, with a net loss of 239.8 million dollars (roughly €209.8 million). Both shares dropped on the numbers: MARA more than 5 per cent to 10.67 dollars, CleanSpark more than 6 per cent to 12.69 dollars.

The stack is going out the door

For investors who treat mining shares as indirect bitcoin exposure, this is the figure that counts. MARA mined 2,422 bitcoin during the quarter at an average price of 71,325 dollars (roughly €62,409) and sold 2,213 at an average of 73,078 dollars (roughly €63,943). Its own holdings fell 29 per cent to 35,577 bitcoin, worth around 2.1 billion dollars at present (roughly €1.84 billion). Hashrate went the other way, up 22 per cent to 70.3 EH/s.

In other words: more is being mined and almost all of it is being sold. Anyone who bought a mining share assuming the company was stacking coins on their behalf needs to revisit that assumption. CleanSpark still holds 13,924 bitcoin, eleventh among listed companies, with 202.6 million dollars in cash (roughly €177.3 million), 2.7 billion dollars in total assets (roughly €2.36 billion) and 1.8 billion dollars in long-term debt.

Why the power is going to AI

The reason sits in the spread per megawatt hour. Compute for AI and high performance computing earns somewhere between 1,500 and 3,500 dollars per megawatt hour on sector figures, against 80 to 120 dollars for bitcoin mining. That is not a gap you close with more efficient machines.

The contracts that follow are sized accordingly. CleanSpark signed a twenty-year triple-net lease worth 6.6 billion dollars (roughly €5.78 billion) for its Sandersville site and has more than 1.8 gigawatts of capacity. TeraWulf, smaller with 44.8 million dollars in quarterly revenue (roughly €39.2 million), already draws 31.9 million dollars of that (roughly €27.9 million) from high performance computing, so 71 per cent, and signed a twenty-year contract for 401 megawatts with projected revenue of 33 billion dollars (roughly €28.9 billion). Across the sector, more than 70 billion dollars of capital has now gone into this shift.

MARA chief executive Fred Thiel framed it as mining having laid the foundation, with digital infrastructure expanding the value on top of it. CleanSpark president Gary Vecchiarelli spoke of converting infrastructure optionality into durable cash flows. That is boardroom language for: the old model does not pay enough.

What this means for you

If you hold mining shares as a substitute for bitcoin itself, that reasoning holds up less and less. These companies are becoming landlords of power and space, with a shrinking bitcoin operation attached. The risk profile shifts accordingly, away from the bitcoin price and towards construction risk, debt load, and whether one large tenant keeps paying for twenty years.

If you want bitcoin exposure, buy bitcoin or a product that actually holds the coin, and judge a mining share for what it now is: an infrastructure business. In the next quarterly report, do not look at the amount mined but at three other lines — how much bitcoin was sold, how much of the revenue comes from outside mining, and how long-term debt compares with cash. And note that these contracts are concentrating the sector around a handful of AI buyers, a risk today's share prices barely reflect.

Sources: MARA Holdings (Q2 2026 results), CleanSpark (results for the quarter to 30 June 2026), TeraWulf (Q2 2026 results), The Block (6 August 2026), CoinDesk (6 August 2026). Last checked: 7 August 2026.