BTC Mining Centralization: 6 Pools Hold 95% of Hashrate

Bitcoin mining centralization has surged in 2025, with the top six pools accounting for 95% of the network’s hashrate. Foundry leads with 30%, followed by “AntPool & friends”—an estimated 40% share when including proxy mining pools—while ViaBTC, F2Pool, and MARA Pool control 14.5%, 10%, and 5%, respectively. This concentration prompted the creation of a Mining Centralization Index, which measures the cumulative hashrate share of the largest pools. Proxy mining pools linked to AntPool mask true network centralization. Smaller pools such as Poolin, Binance Pool, and CloverPool use nearly identical block templates, inflating decentralization metrics based solely on coinbase tags. When combined, “AntPool & friends” rival Foundry’s dominance in the updated index. The Bitcoin mining centralization trend raises concerns about censorship resistance and 51% attack risks. A single pool holding 40% of hashrate has roughly a 50% chance of winning six consecutive blocks. To restore balance, supporting small pools like Ocean and DEMAND and encouraging more independent mining operations are essential to bolster network stability.