On September 16, BTC.com, the mining pool of Bitmain, lost its years’ long first place to another China-based mining pool Poolin whose real-time hashrate read 13,378.00 PH/s at some point.

BTC.com, supported by the advantages of Bitmain’s bitcoin mining machines, has been the largest bitcoin mining pool for years. In the first half of 2018, the hashrate of mining pools under Bitmain (with BTC.com, AntPool and ViaBTC included) approaching the dreaded 51% threshold had triggered massive concerns that Bitmain might stage a 51% attack.

However, bitcoin mining hashrate has been more decentralized as smaller pools make gains since entering 2019. The rankings of mining pools saw significant shift especially over the second half of the year, with Poolin moving to the second place and even the first place at some point.

Though BTC.com climbed back to its dominant position soon, the upheaval marks that bitcoin mining hashrate has been more distributed among top mining pools, and the competition among these big pools is becoming fiercer.

Bitcoin hashrate distribution in 2013, 2018 and past year, respectively (Sources: btc.com)

Founded in November 2017, Poolin’s rapid rise to top mining pool generates as much fear as admiration. Since BTC mining pool went live in July 2018, its bitcoin hash power has been growing continuously. Apart from its increasing bitcoin hashrate, its hashrate of LTC and ZEC has steadily ranked No.1 among the global mining pools.

Poolin made its latest exposure when its cofounders (CEO Zhibiao Pan; COO Fa Zhu; and CTO Tianzhao Li) – three former employees of Bitmain who helped establish BTC.com – was sued by Bitmain for allegedly violating their non-compete agreement.

As of press time, data shows that BTC.com’s hashrate has seen an increase of 0.37% in the past 24 hours, and that of Poolin has dropped by 2.99%, with its real-time hashrate reading 13,069.00 PH/s and BTC.com marking 13,560.00 PH/s. In terms of bitcoin hashrate distribution, BTC.com accounts for 18.0% in the past week, followed by Poolin with a share of 15.2%, and China’s oldest bitcoin mining pool F2Pool ranks third accounting for 13.8%.

Since its operation in late 2010, mining pools grow and shrink. According to incomplete statistics, nearly 20 pools that used to have big names have chosen to shut down. While China-based mining pools still dominate the market with a lion share above 75%.