Bitcoin鈥檚 mining difficulty fell 11.16% on Saturday to 125.86 trillion at block height 935,424.

The move marked the largest single negative adjustment since China鈥檚 July 2021 mining ban and was described by developer Mononaut as the 10th largest negative percentage adjustment in Bitcoin鈥檚 history.

What changed at the retarget

Difficulty reset down from 141.67 trillion after average block times drifted to about 11.4 minutes, above the network鈥檚 10-minute target.

The adjustment followed a sharp pullback in computing power, with total hashrate down roughly 20% over the past month.

Bitcoin鈥檚 hashrate fell about 11% in the past week to around 863 EH/s, down from near all-time highs above 1.1 ZH/s reached in October.

For historical context on network compute, see Bitbo鈥檚 hashrate chart.

Price slump and storm curtailments

The hashrate drawdown coincided with bitcoin falling more than 45% from an October all-time high above $126,000, bottoming near $60,000 on Feb. 5 before rebounding to around $68,800.

Separately, Winter Storm Fern in late January forced miners across U.S. power regions to curtail operations, with prior reporting estimating roughly 200 EH/s went offline and Foundry USA鈥檚 hashrate falling about 60%.

Miner revenue hits record lows

Luxor鈥檚 Hashrate Index showed hashprice hitting an all-time low of $33.31 per petahash per day on Feb. 2, with a daily average low of $34.91/PH/s/day on Feb. 1.

The $40/PH/s/day level is widely viewed as a threshold where miners decide whether to keep machines running.

Ben Harper, Luxor鈥檚 Director of Derivatives, told Blockspace:

鈥淭he $40/PH/s/day level is widely seen as the threshold at which miners must decide whether to keep machines running.鈥?/p>

The average cost to mine one bitcoin was cited at around $87,000, versus spot trading near $69,000.

The difficulty drop can mechanically improve odds of earning rewards for miners that remain online, but the impact depends on price and operating conditions.