Bitcoin Mining Difficulty Drops 9.91% as Hashrate Leaves the Network

Bitcoin's mining difficulty fell 9.91% at the retarget on 13 June, one of the largest downward adjustments on record. The parameter dropped from 138.96 trillion to 125.19 trillion in a single step. Ahead of the move, hashrate, the total computing power miners point at the network, had slid to roughly 967 exahashes per second. Bitcoin was trading near $64,007 at the time, and the Crypto Fear & Greed Index, a sentiment gauge running from 0 to 100, sat at 13 in extreme-fear territory. A cut of that size is arithmetic, not interpretation. Machines switched off.

Blocks had been coming in slow

Difficulty sets how hard it is to find a valid bitcoin block. The network recalculates it roughly every two weeks with a single objective, which is to keep blocks arriving about every ten minutes no matter how much hardware is competing. When machines join, blocks come faster than the target and the next retarget revises difficulty upward to slow them down. When machines leave, blocks lag and the next retarget cuts it. That is why the direction and size of an adjustment read as evidence. A 9.91% cut means the previous two weeks of blocks were found meaningfully slower than the ten-minute target, and that only happens if hashrate left the network.

The numbers: 138.96T to 125.19T, and a hashrate estimate that varies

The difficulty values themselves are exact, 138.96 trillion before the retarget and 125.19 trillion after. Hashrate is not measured that way. It is inferred from how quickly blocks are found, and the readings ahead of the adjustment differed by source. The widely cited figure was roughly 967 EH/s. One report from the ASIC-mining industry put it lower, at 918 EH/s; that reading appears in a single source and stands unverified. We could not establish which estimate sits closer to the true figure.

Difficulty: 138.96T to 125.19T, a 9.91% decline at the 13 June retarget.
Hashrate: roughly 967 EH/s ahead of the adjustment.
A single ASIC-industry report put hashrate lower, at 918 EH/s.
Bitcoin near $64,007 at the time of the retarget.
Crypto Fear & Greed Index at 13.

Why the machines went dark

The immediate cause was margin. A mining rig earns a share of block rewards in proportion to its hashrate and pays for electricity either way, so when the bitcoin price falls far enough, the least efficient machines cost more to run than they bring in, and operators switch them off. Bitcoin had broken below $60,000 earlier in the month, touching an intraday low of $59,743 on 5 June, and older hardware powering down through that drawdown is the explanation reported for the hashrate decline. Behind it sits a slower structural shift. Miners have been redirecting sites, power contracts and capital toward artificial intelligence and high-performance computing hosting, which pays for compute capacity on contracted terms rather than on the block reward. Capacity that moves for that reason does not necessarily come back when the bitcoin price does.

The cut pays whoever stayed

A difficulty cut is a direct transfer of revenue to whoever is still hashing. The block subsidy does not change. The same bitcoin issued each day is divided among less competing hardware, so every machine still running earns more of it per unit of power consumed than it did the day before. That is how the network is meant to stabilize itself, with the cheapest power and the newest hardware absorbing the share of those that left. Whether the relief holds depends on price. If bitcoin stays near the levels seen at the retarget, it is real; if hashrate returns because mining is briefly profitable again, the next retarget in roughly two weeks will claw part of it back. The number to watch is the sign of the following adjustment, positive if the machines came back, negative again if they did not.