Bitcoin's network difficulty underwent its latest adjustment at block height 921,312 on October 29, 2025, rising 6.31% to a new all-time high of 155.97 trillion (155.97T), according to CloverPool data. Meanwhile, the network's average hashrate also climbed to 1.12 Zettahash per second (ZH/s), equivalent to 1.12×10²¹ hashes per second.
Difficulty and Hashrate Reach New Peaks
This adjustment marks the first time Bitcoin's difficulty has surpassed the 155T threshold. Prior records were set in August 2025, but the 6.31% increase is among the largest single adjustments in recent months. The average hashrate rose from around 1.05 ZH/s before the adjustment, reflecting miners' continued deployment of more efficient ASIC machines and aggressive addition of new computing power to compete for block rewards.
Impact on Miners and the Ecosystem
Higher difficulty translates to increased mining costs. With the current hashrate of about 1.12 ZH/s, daily revenue per Exahash (EH/s) has fallen to roughly 0.08 BTC (equivalent to several thousand dollars at current prices). Intensified competition is forcing smaller miners to exit or consolidate, while large players such as Marathon Digital and Riot Platforms continue to expand their share due to scale advantages and low-cost electricity. Additionally, elevated difficulty strengthens Bitcoin's security — the cost of a 51% attack now exceeds tens of billions of dollars.
Next Adjustment Outlook
CloverPool estimates the next difficulty adjustment will occur in approximately 12 days, i.e., early November 2025. If the current hashrate level persists or grows, difficulty could rise further. Bitcoin's mining difficulty auto-adjusts every 2,016 blocks (roughly two weeks) to maintain an average block interval of 10 minutes.
This difficulty milestone comes amid relatively stable Bitcoin prices, which have fluctuated between $68,000 and $72,000 over the past month. Miners' revenue primarily derives from block subsidies and transaction fees. Following the 2024 halving, the block reward dropped to 3.125 BTC, further elevating the importance of mining efficiency.
Historical Context and Industry Trends
Bitcoin's network difficulty has surged over 345% from approximately 35T in early 2023 to the current 155.97T. This growth is driven by global carbon-neutral policies pushing miners toward green energy, widespread adoption of immersion cooling technology, and rapid expansion of large-scale mining farms in North America and the Middle East. The simultaneous rise in hashrate and difficulty underscores the maturation of Bitcoin as a decentralized compute network.
Market analysts caution that if BTC prices fail to keep pace, sustained difficulty increases could squeeze miner margins, potentially forcing older mining rigs (e.g., S19 series) into premature retirement. However, in the long term, hashrate competition remains the bedrock of Bitcoin's security and a core manifestation of its Proof-of-Work consensus mechanism.