The Bitcoin (BTC) 30-day mean hash rate has fallen 19% since November 2025, sliding from 1,108 EH/s to 898 EH/s. Glassnode data shows the nine-month decline is the longest in the network’s history.

The slide coincides with the largest capital migration miners have ever staged. Public mining firms hold over $70 billion in AI contracts, and converted capacity may never return.

Nine Months of Decline Sets a Bitcoin Hash Rate Record

Bitcoin has seen only two comparable drawdowns in its modern era, and both ended quickly. The current one has not ended at all, according to Glassnode data.

The 2021 collapse cut deeper in percentage terms. However, it reversed within six months as Chinese hardware relocated to the US and Central Asia.

The 2024 dip was a routine purge of inefficient rigs after the halving. New machines replaced the lost capacity within a quarter.

The current slump is different on both axes. The network has shed roughly 210 EH/s in absolute terms. That is more hashpower than the entire network possessed in early 2021. Moreover, the 30-day average shows no bottom formation heading into August.

The squeeze has already claimed casualties. Poolin, once the world’s largest mining pool, filed for Chapter 11 protection in late July.

Mining Difficulty Turns Negative for the Second Time Ever

The depth of the current slump is not its most alarming feature. Its rarity is.

Data from Luxor’s Hashrate Index shows network difficulty now sits 1.1% below its level one year ago. That is the first negative year-over-year reading since August 2021, when China’s ban drove the metric to −21.2%.

Difficulty has printed sub-zero annual readings only twice in Bitcoin’s history. Both red zones on the chart mark a mass departure of miners.

The mechanics, however, could not be more different. The 2021 dip was violent but temporary, because the rigs survived and simply changed address.

The 2026 version is shallower but structural. Miners are signing 12 to 20-year AI hosting leases on the same power capacity that once ran ASICs. BeInCrypto has previously examined whether mining is becoming an energy and infrastructure business.

Difficulty has contracted 19.9% from its November 2025 peak near 156 trillion to 126.23 trillion. That ranks among the deepest sustained contractions of the ASIC era.

Popular X account BitcoinArchive noted that Bitcoin has spent only 10 days trading below its production cost since 2017. The account estimates the current cost near $54,939, assuming electricity at $0.06 per kWh. Each negative difficulty adjustment also lowers production costs for the miners who stay.

What the Miner Exodus Means for BTC at $64,000

BTC traded near $64,078 at press time, up 0.9% over the past 24 hours, per BeInCrypto market data. The price remains roughly 49% below its October 2025 peak. That collapse triggered the exodus.

Hashprice hovers near $30–32 per petahash per day, below breakeven for older fleets. Industry estimates suggest 15–20% of machines run at a loss. Meanwhile, public miners sold over 32,000 BTC in the first quarter to fund their transition.

The AI contracts explain why the capacity is not coming back. Hut 8 reports $26.6 billion in contracted AI portfolio value, while Core Scientific leases around 1.1 GW to CoreWeave. TeraWulf signed a 20-year lease with Anthropic worth about $19 billion. IREN and Cipher Mining added deals with Microsoft and AWS worth $9.7 billion and $5.5 billion, respectively.

AI hosting reportedly pays 3 to 25 times as much per megawatt as mining. The diagnosis, therefore, reads as a cyclical trigger with a structural exit. Falling prices triggered the slide, but long-term contracts prevented a historical rebound.

Not everyone sees danger. Coinbase CEO Brian Armstrong has dismissed fears that the energy shift will hurt the BTC price.

Chamath Palihapitiya, in contrast, calls the shift structural for miners. Bitwise Europe research head André Dragosch adds that miners could regret the pivot if profitability recovers.

The near-term signal to watch is the difficulty chart. If the year-over-year reading stays negative through autumn, the network will confirm its first sustained security-budget contraction ever. Either fresh capacity replaces the AI defectors in 2027, or Bitcoin faces its next rally with a thinner hashpower cushion.

Source: BeInCrypto