Bitcoin mining in the US is growing, but miners are struggling to stay profitable

American mining companies are reporting increased bitcoin production, even as profitability continues to decline. Rising network difficulty and block reward adjustments are squeezing margins across the industry—despite solid operational performance.

Pools are working harder, but competition intensifies

MARA (formerly Marathon Digital), one of the largest players in the market, mined 950 BTC in May—up 35% from April and the company’s best result since the April 2024 halving. According to MARA, its private mining pool confirmed 282 blocks, a 38% increase month over month. The company averaged over 30 bitcoins per day, with MARA’s share of total miner rewards reaching 6.5%.

The improved figures are attributed to MARA’s growing hash rate: its total computing power hit 58.3 EH/s. Despite strong output, the company chose not to sell any of its bitcoin in May. By the end of the month, MARA held nearly 50,000 BTC on its balance sheet—worth about $5.2 billion at market prices. This cements its position as one of the largest public bitcoin holders globally.

Riot Platforms, another major US miner, also reported increased output—514 BTC in May, which is 11% more than in April and nearly 2.5 times higher than in May 2024. However, unlike MARA, Riot continues to sell part of its mined coins. The company sold 500 BTC last month, generating around $51.3 million in revenue. Riot also announced plans to expand infrastructure and hire new staff across the company.

Profitability drops as miners are forced to adapt

As the bitcoin network evolves, mining becomes increasingly complex. The algorithm adjusts upward in difficulty whenever new computing power joins the network, in order to maintain the steady issuance of coins. This increases not only computational demand, but also infrastructure requirements.

At the same time, the miner profitability index no longer reflects the strong returns seen earlier in May. The metric fell from $58.67 to $52 per PH/s—even as bitcoin's price hit a record $112,000—highlighting that mining profits are nearing their ceiling.

Mining today isn’t just about «digging coins», but about managing a capital-intensive business shaped by multiple factors—from electricity and hardware costs to Federal Reserve policy and crypto regulation. Over the coming months, success will likely depend less on the scale of mining farms and more on flexibility, financial discipline, and timely modernization