China's share of Bitcoin hashrate fell from 75.5% in September 2019 to 46% in April 2021, even before a crackdown; United States' share rose from 4.1% to 16.8%
Context & Ripple Effects
The Cambridge Judge data shows China's grip on Bitcoin was already slipping before Beijing moved against miners: its hashrate share fell from 75.5% in September 2019 to 46% by April 2021, while the United States climbed from 4.1% to 16.8%. The crackdown on mining operations that followed turned this gradual erosion into collapse.
Within weeks, research showed China's share dropping to zero between May and July as machines went dark or crossed borders — a shift so abrupt the network cut mining difficulty 28% to keep remaining miners profitable. Later coverage complicated the 'China is out' narrative entirely.
First-order effects
- Miners fleeing China found the network temporarily easier to mine: with hashrate offline, the protocol adjusted difficulty down 28%, cushioning margins for operators who relocated quickly.
- The United States and Kazakhstan absorbed the displaced fleet — the US reaching 35% of global hashrate by August and Kazakhstan 18%, per the FT-reported research.
Second-order effects
- Relocation shifted demand for power and hosting toward North American and Kazakh grid operators, entrenching new mining hubs whose economics now depend on energy prices rather than proximity to chip supply chains.
- China's exit forced Western pools and hardware buyers to re-map counterparty risk around jurisdictions they had previously treated as peripheral.
Third-order effects
- The ban proved porous: Bloomberg-reported research found China's hashrate share back at 21.1% by early 2022 through covert mining, and Reuters reported a rebound to 14% by late October 2025 — evidence that prohibition redirects mining underground rather than eliminating it.
- If the pattern holds, national bans reshape where legal mining concentrates while leaving determined states with a shadow share, making hashrate geography a recurring policy problem rather than a settled outcome.
The trend: Bitcoin mining is migrating out of single-country dominance into a dispersed but contested map, where state crackdowns relocate hashrate faster than they can extinguish it.