The Bitcoin network has just gone through one of its sharpest stress tests in years, after a sudden drop in mining activity triggered the biggest downward difficulty adjustment since China’s mining ban in 2021.
Key Takeaways
Bitcoin’s mining difficulty dropped 11.16%, the largest decline since 2021, after a sudden loss of hash power.
Extreme winter weather and falling prices forced up to 20% of miners offline, especially in the U.S.
Despite the disruption, the network adjusted smoothly and continued operating without issues.
On February 7, Bitcoin’s mining difficulty fell by 11.16%, reflecting a rapid loss of hashing power as an estimated 12% to 20% of miners went offline in early February. Data from mempool.space shows roughly 10% of hash power disappearing in a short window, confirming how closely mining activity still tracks price and operational conditions.
Why hash power suddenly went offline
The disruption was driven by a mix of extreme weather and collapsing miner profitability. A major winter storm in the United States, Winter Storm Fernan, forced large-scale mining facilities – especially in Texas – to temporarily shut down. Many of these operators rely on curtailment contracts, meaning they switch off mining rigs and sell electricity back to the grid during peak demand rather than operate at a loss.
The impact was visible at the pool level. Foundry USA, then the largest mining pool globally, saw its hash rate plunge by roughly 60%, dropping from around 328 EH/s to near 139 EH/s at the worst point.
At the same time, Bitcoin’s price was under heavy pressure. After peaking above $126,000 in October 2025, BTC fell more than 45%, bottoming near $60,000 on February 5. That move crushed miner profitability, pushing hashprice down to roughly $31.5–$34.8 per PH/s, dangerously close to break-even for many operators. Public miners such as CleanSpark and IREN have reported cash costs in the $26–$30/PH/s range, leaving almost no margin for error.
What the difficulty adjustment changed
As hash power fell, block times stretched to more than 11 minutes on average. The February 7 difficulty adjustment brought immediate relief. Difficulty dropped from roughly 141.67 T to 125.86 T, allowing blocks to be mined faster again, with average block times falling back toward the 7–9 minute range.
Despite the slowdown, the network functioned normally. No chain splits or consensus issues occurred, underlining Bitcoin’s ability to self-correct even during localized infrastructure failures.
Signs of miner stress are mounting
The pressure on miners is starting to show elsewhere. On February 5 alone, miners sent an estimated 24,000 BTC to exchanges, the largest single-day outflow on record. That kind of movement is often interpreted as miner capitulation or forced selling to cover operating costs during sharp downturns.
At the industry level, the post-halving reality is accelerating a structural shift. Several publicly listed mining firms, including Cipher Mining, IREN, and Hut 8, are increasingly pivoting toward AI and high-performance computing. By late 2026, some expect Bitcoin mining to contribute less than 20% of total revenue as data centers are repurposed for AI workloads.
What comes next
With weather conditions improving and prices stabilizing, miners are gradually bringing hardware back online. The next difficulty adjustment, expected around February 19–20, is currently projected to rise by about 5.6%, signaling a partial recovery in network hash rate.
For now, the episode serves as a reminder that while Bitcoin mining is global, it remains exposed to real-world constraints – energy markets, weather, and price cycles – and that the protocol’s difficulty mechanism remains one of its most important stabilizers.
