Bitcoin mining stocks extended their recovery in September, outpacing Bitcoin even as industry economics remain under pressure and hardware payback periods stretch longer.

According to The Miner Mag’s latest industry update, shares of Cipher Mining (CIFR), Terawulf (WULF), Iris Energy (IREN), Hive Digital Technologies (HIVE) and Bitfarms (BITF) surged between 73% and 124% over the past month. By contrast, Bitcoin (BTC) slipped more than 3% over the same period.

Several Bitcoin mining stocks are trading at yearly or all-time highs. Source: The Miner Mag

The rally in mining stocks comes despite continued pressure on industry fundamentals. The Bitcoin network’s next difficulty adjustment is projected to rise another 4.1%, which would “mark the first epoch with an average hashrate above the zetahash mark,” The Miner Mag reported.

That 1 zetahash milestone was first reached in September, based on Bitcoin’s 14-day moving average hashrate. Yet the achievement has done little to ease profitability strains.

Hashprice remains stuck below $55 petahash per second, pressured by rising network activity, while transaction fees have slipped under 0.8% of monthly rewards — a sign of weaker onchain activity.

Bitcoin mining update for August 2025. Source: The Miner Mag

Even so, investors are rewarding miners pursuing GPU and AI pivots, The Miner Mag said. Hive Digital is accelerating its transition into AI data center infrastructure, Iris Energy is ramping up with Blackwell GPUs, and Terawulf has drawn momentum from its high-performance computing partnership with Google.

Related: Bitcoin network mining difficulty climbs to new all-time high

Bitcoin miner accumulation continues

Faced with tighter profit margins, rising costs and growing competition, Bitcoin miners are increasingly turning to diversification strategies to stay afloat.

Beyond pivoting resources toward AI and high-performance computing, many miners have also embraced a treasury strategy, holding onto more mined Bitcoin in anticipation of a future price surge.

Coinpectra reported on this trend in January, highlighting a notable shift in miner accumulation that gained momentum through 2024 as companies retained a larger share of their production.

“In 2024, a notable shift emerged among Bitcoin miners, with many opting to retain a larger portion of their mined Bitcoin or refraining from selling altogether,” Digital Mining Solutions and BitcoinMiningStock.io wrote in a January report.

Miners appear to be doubling down on this strategy in September, with Glassnode data showing wallet balances rising for three consecutive weeks. On Sept. 9, net inflows peaked at 573 BTC — the largest daily increase since October 2023.

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