Bitcoin BIP110 Fork Lags Main Chain Amid Replay Attack Risks

A minority chain fork of Bitcoin, initiated by the BIP110 proposal, has emerged but is already struggling to keep pace with the main network, raising questions about its viability and posing operational risks for users. The split occurred on August 9, 2026, when nodes enforcing the BIP110 rules rejected a block mined without the required signaling, creating a separate, lagging branch of the blockchain.

The divergence began at block height 961,632. According to reports, the mining pool AntPool produced a block that did not include the BIP110 signal, while the pool Roughnecks, operating through OCEAN, mined a competing block that did. As a result, software nodes configured to enforce BIP110 rejected AntPool's block and followed the alternative chain. The majority of the network, however, continued extending the original Bitcoin chain under the existing consensus rules, quickly widening the gap between the two branches.

By early August 9, the main Bitcoin chain had advanced to block 961,654, while the BIP110-enforcing branch was at block 961,633, leaving it 21 blocks behind. This significant lag underscores a fundamental challenge: the minority fork has attracted very little mining...