TLDR
- Bitcoin mining stocks surged 73-124% in September, far outperforming Bitcoin’s 3% decline
- Mining companies pivoting to AI infrastructure are driving investor interest, with stocks hitting yearly highs
- Industry fundamentals remain challenging with hashprice below $55/PH and rising difficulty adjustments
- Miners are accumulating Bitcoin reserves as a treasury strategy while diversifying into high-performance computing
- Combined market cap of major mining firms has doubled to $47 billion from $21 billion earlier this year
Bitcoin mining companies are experiencing a remarkable stock rally even as the core business faces mounting challenges. September delivered exceptional gains for major mining firms, with their combined market capitalization approaching $50 billion.
Which Bitcoin mining stocks are institutions betting on? 🤔
Latest 13F filings show $IREN, $CIFR, $CORZ, $APLD, and $MARA leading gains in new positions + $$ inflows.
Some other observations 🧵 pic.twitter.com/jeFyrz5Vv0
— Cindy Feng (@itsCindyFeng) September 12, 2025
Leading the charge, Cipher Mining, Terawulf, Iris Energy, Hive Digital Technologies, and Bitfarms posted gains between 73% and 124% over the past month. This performance stands in stark contrast to Bitcoin itself, which dropped more than 3% during the same period.
The rally pushed several mining stocks to yearly or all-time highs. Iris Energy reached $36.38, while Applied Digital hit $19.60. Bitfarms jumped 17% to $2.61 in a single trading session, bringing its market cap to $1.47 billion.
AI Pivot Drives Investor Interest
The stock surge appears driven by mining companies’ strategic shifts toward artificial intelligence and high-performance computing. Hive Digital is accelerating its transition into AI data center infrastructure. Iris Energy is ramping up operations with Blackwell GPUs.
Terawulf has generated momentum through its high-performance computing partnership with Google. These diversification efforts are resonating with investors despite challenging mining fundamentals.
The Bitcoin network’s difficulty adjustment is projected to rise another 4.1%. This increase would mark the first time the average hashrate exceeds one zetahash, a milestone first reached in September based on Bitcoin’s 14-day moving average.
However, profitability remains under pressure. Hashprice sits below $55 per petahash per second, while transaction fees have fallen under 0.8% of monthly rewards. This decline signals weaker onchain activity affecting miner revenues.
Treasury Strategy Takes Hold
Faced with tighter margins and rising costs, miners are embracing Bitcoin accumulation strategies. Companies are holding onto more mined Bitcoin rather than selling immediately to cover operational expenses.
This treasury approach gained momentum throughout 2024. Glassnode data shows miner wallet balances rising for three consecutive weeks in September. On September 9, net inflows peaked at 573 BTC, marking the largest daily increase since October 2023.
The combined market capitalization of 15 major mining firms has doubled from a low of $21 billion earlier this year. Iris Energy leads with a $9.4 billion market value, followed by other industry players posting strong gains.
Mining stocks have outperformed Bitcoin over the past month, cementing their position as beneficiaries of renewed digital asset infrastructure investment. The sector continues attracting capital despite ongoing operational challenges and competitive pressures.
