Bitcoin Mining Difficulty Rises 1.31% to 127.45 Trillion as Hashrate Idles About a Fifth Below Its Peak
The Sept 5 retarget at block 965,664 lifted difficulty by 1.31% to roughly 127.45T, exactly reversing the cut of Aug 23, while seven-day hashrate sits near 915 EH/s, well below last year's record, as miners keep diverting power to AI workloads.
Bitcoin's mining difficulty adjusted upward by 1.31% at block 965,664 on Friday, September 5, taking the figure to about 127.45 trillion, according to mempool.space data. The move exactly reverses the 1.31% cut at the previous retarget on August 23 and leaves difficulty well below the 148.25 trillion the network started 2026 with.
The numbers
New difficulty: 127,450,789,715,843, up from 125.81 trillion; the 2026 low was 124.93 trillion on June 13.
Seven-day average hashrate: about 913 to 915 EH/s on September 5 and 6 per mempool.space, with CoinWarz showing a 30-day decline of 10.5%.
Next retarget is expected around September 19. Early estimates diverge, with CoinWarz projecting roughly +1.2% and mempool.space +3.5% with only 4% of the epoch complete, so treat both as noise for now.
The adjustment was not the one forecasters expected: as late as the afternoon of September 5, CoinWarz was projecting a further 0.94% decrease. Difficulty adjusts every 2,016 blocks to keep block times near ten minutes, so the small increase means blocks in the past two weeks came slightly faster than target.
A bear market in hashrate
The bigger picture is a network that has been shrinking for most of the year. Bitcoin.com's Jamie Redman counted the August 23 adjustment as the 17th of 2026, with ten decreases against seven increases, and estimated roughly 150 EH/s of capacity sidelined. The Crypto Times reports hashrate has now spent 316 consecutive days below its all-time high, at about 914 EH/s versus a late-October 2025 peak near 1,151 EH/s on a seven-day basis, a gap of about 20%. Peak figures vary by smoothing window; CoinWarz's one-day series shows a higher 1.44 ZH/s high on September 20, 2025.
Rapha Zagury, chief executive of Twenty One Capital, told the Bitcoin Asia 2026 conference on August 28 that the industry is living through the first bear market in hash rate that we've ever seen in Bitcoin history, as reported by Bitcoin.com. Redman's own summary: this has not been a year of steady hashrate expansion but a grind of miner capitulation, sharp rebounds and repeated failures to make those recoveries stick.
Where the power went
Miners are not going bankrupt so much as changing tenants. Hut 8 signed a 352 MW, 15-year AI hosting lease valued at $9.8 billion; Bitdeer struck a 121 MW, 16-year deal worth $4.7 billion; IREN cut its bitcoin mining from about 50 EH/s to 23.2 EH/s; and Keel Infrastructure shut down all of its US bitcoin mining, according to Bitcoin.com and The Crypto Times. For the miners that remain, a lower difficulty means a larger share of the block subsidy per unit of hashrate, which is the network's built-in incentive to keep the lights on until either price or hosting economics shift again.
Data note: the September 5 retarget figures come from live network explorers (mempool.space, CoinWarz) read on September 6 rather than from a news report, and difficulty and hashrate values are rounded.