Bitcoin hashrate back above 1 zettahash as difficulty hits record

Bitcoin's computing power climbed back above 1 zettahash per second on October 22, a level last seen in March. Mining difficulty set a record near 140.58 trillion. More machines are now chasing the same fixed reward.

BlocksBridge Consulting supplied the hashrate reading. Its Miner Weekly newsletter reported on October 22 that the seven-day average had crossed 1 zettahash for the first time since March 3. On-chain difficulty data from CoinWarz shows the network at 140,577,680,051,919 as of October 24, the level set at the October 16 adjustment.

The difficulty climb, in numbers

The record is the network answering a simple pressure. More computing power joined, so difficulty rose to match. That mechanism keeps new blocks landing about 10 minutes apart, whatever the number of miners.

On October 16 difficulty jumped 5.92 percent, from 132.72 trillion to 140.58 trillion, the largest upward move in months, according to CoinWarz. It had barely moved at the October 3 adjustment, slipping 0.03 percent, before that jump. The protocol recalculates every 2,016 blocks, roughly every two weeks. A higher reading also lengthens how long it takes to mine a single coin for any given rig.

Watch the next change, due around October 29. Here the two data providers disagree. CoinWarz estimates a further 6.8 percent rise, to about 150.13 trillion. BlocksBridge projects a smaller 5.16 percent. Both point the same way.

Why power rose while miners chased AI

Several large public miners have spent the year moving rigs away from Bitcoin and toward AI and high-performance computing, where the contracts pay more steadily. The gauge had sat under 1 zettahash since early March, a stretch that lined up with that migration. BlocksBridge estimated publicly traded miners cut their realized Bitcoin hashrate by about 23 percent. Their AI and HPC revenue rose 52 percent quarter over quarter through the second quarter of 2026. The gear they unplugged, BlocksBridge said, amounted to roughly 1.5 billion dollars of mining hardware.

So the network's total power should have dropped. It did the opposite. Someone filled the gap. Private operators, overseas fleets and newer, more efficient machines appear to have absorbed the freed-up share, carrying the network-wide hashrate back to a record pace.

For the miners who stayed, that is cold comfort. "That's hardly the breathing room remaining miners might have expected from the AI migration," BlocksBridge wrote. Higher difficulty means each machine earns a thinner slice of the same block reward, which feeds straight into whether mining still pays.

What to watch

Not everyone reads a rising hashrate as pure cost pressure. Ki Young Ju, founder and CEO of the analytics firm CryptoQuant, posted on X that a higher hashrate points to stronger network security and better store-of-value fundamentals. His firm's on-chain data put the true hashrate near 1,000 exahash per second on October 22, close to the seven-day average.

Both readings can sit together. A more secure chain and thinner mining margins do not cancel out. The open question is how long operators keep spending to defend a shrinking per-machine reward.

That October 29 retarget is the near-term tell. Another rise would confirm that the capacity freed by the AI shift has been more than replaced. Neither BlocksBridge nor CryptoQuant has said how much of the new power is private versus public, so the full map of who is mining stays blurry.