Bitcoin mining firms are turning to billions in fresh funding as high energy prices squeeze profits.

Facing soaring energy costs, Bitcoin (BTC) miners in the U.S. are building war chests worth billions as competition for resources intensifies and profitability following Bitcoin’s latest halving remains under pressure, the Financial Times reports.

Companies like Marathon Digital, Riot Platforms, and CleanSpark have raised more than $3.7 billion since November 2024 through zero or near-zero coupon convertible notes. Much of the money has gone into buying Bitcoin to strengthen reserves as the largest crypto by market capitalization surpassed the $100,000 milestone.

Marathon CEO Fred Thiel said their business strategy is to “accumulate as much Bitcoin as [we] can,” with the company now holding nearly 45,000 BTC, valued at over $4.4 billion.

Still, miners are up against some big challenges. Energy costs keep climbing, and the Bitcoin hash rate is at an all-time high. On top of that, Bitcoin’s latest halving cut mining rewards in half, dropping from 6.25 BTC to just 3.125 BTC per block.

James Butterfill, head of research at CoinShares, says the firm sees a “stratospheric rise in the Bitcoin hash rate, highlighting a massive amount of new hardware coming online, making those at the higher end of cost of production much more vulnerable, if we see a price correction.”

Miners are also competing with artificial intelligence developers for access to the power grid. Some companies, like Hut 8 and Hive, are pivoting to lease their data centers to AI firms to offset costs, the report reads. Others, like Marathon, are expanding operations to countries with surplus energy, such as Kenya and Paraguay.