Did China have 65% of the global hash rate in 2015?

External question — Bitcoin Stack Exchange Author: Geremia Original post: https://bitcoin.stackexchange.com/questions/131091 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Bier, The Blocksize War (2021) claims in ch. 4 that: China was regarded as having around 65 percent of the global hashrate […] [during the] Scaling conference series [that] took place in Hong Kong on December 6 and 7, 2015. Is this true? How was was this estimated? Today, according to the Global Hashrate Heatmap , China only has 11.7% of the global hashrate market share (110 EH/s), and the USA is the world's leader with 35.6% (335 EH/s), with US-based Foundry being the #1 pool. How could've China's share of the global hashrate declined from 65% to only 12% over the past decade? What caused this?

External answer — Bitcoin Stack Exchange Author: RedGrittyBrick Original post: https://bitcoin.stackexchange.com/a/131094 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. China's global share of hashrate crashed when the chinese government imposed restrictions. https://www.reuters.com/world/china/china-central-bank-vows-crackdown-cryptocurrency-trading-2021-09-24/ However this ban on mining didn't affect Hong Kong and also some illegal mining continues.