Bitcoin BIP-110 Fork Trails Main Chain After Minority Split

Bitcoin's BIP-110 activation attempt triggered a live minority fork on August 9 when enforcing nodes rejected a non-signaling block at height 961,632. According to reports, the majority of miners continued extending the existing network, quickly widening the gap between the two branches. By approximately 01:00 UTC that day, the main chain had reached block 961,654 while the enforcing branch stood at 961,633, placing the fork 21 blocks behind.

The split occurred as the proposal entered its mandatory-signaling phase. AntPool mined a non-signaling block at the critical height, while Roughnecks produced a competing compliant block through OCEAN. Nodes enforcing BIP-110 rejected AntPool's block and followed the alternative branch, while the larger non-enforcing network continued under existing consensus rules.

Support for the proposal had remained minimal before the split. During the previous 2,016-block period, only 51 blocks signaled backing, representing just 2.53% of the total. The BIP-110 activation process required 55% of blocks to signal support during its early phase, but miner participation fell far short of that threshold. The mandatory-signaling requirement now remains in effect through block 963,647, with enforcing nodes rejecting blocks that fail to set version bit 4. Under the proposal's rules, the minority branch would force lock-in at block 963,648.

Despite social-media characterizations, BIP-110 is not a quantum-computing security upgrade. Its official title is "Reduced Data Temporary Softfork," and it proposes temporarily restricting arbitrary data embedded in Bitcoin transactions through seven consensus rules covering scriptPubKeys, OP_RETURN data, witness payloads, and Taproot-related structures. The transaction restrictions are scheduled to take effect at block 965,664 and remain active for 52,416 blocks before expiring.