Bitcoin split into two chains overnight, but a silent miner boycott just halted the enforcing BIP-110 chain

BIP-110, a proposed temporary soft fork restricting some uses of arbitrary data in Bitcoin transactions, entered its mandatory-signaling window with miners producing 59 consecutive non-signaling blocks. Nodes enforcing the proposal were left on a two-block branch, 57 blocks behind Bitcoin’s dominant proof-of-work chain.

As of 6:34 a.m. UTC on Aug. 9, direct explorer data put the dominant chain at block 961,690, while the BIP-110 enforcing branch remained at 961,633. Its latest block was roughly eight hours and 45 minutes old.

BIP-110 mandatory signaling window

The proposal sets temporary consensus limits on several methods of placing arbitrary data in Bitcoin transactions. Its deployment uses a 55% threshold, or 1,109 of 2,016 blocks, and requires signaling from heights 961,632 through 963,647 for nodes that enforce the proposal.

Under the BIP-110 state machine, a compliant enforcing chain that reaches height 963,648 enters LOCKED_IN. The proposed restrictions become ACTIVE only if that chain later reaches height 965,664, one retarget period later. The current split therefore occurred during mandatory signaling; the transaction restrictions remain two stages away.

Bitcoin’s miner output favors the dominant branch

The BIP-110 divergence began at height 961,632, when enforcing nodes started rejecting blocks that did not set version bit 4. A review of the dominant chain’s first 59 block headers in the window found zero bit-4 signals.

The BIP-110 enforcing branch produced two blocks, at heights 961,632 and 961,633, both attributed to miners using OCEAN and both carrying the required signal. By the 06:34 UTC snapshot, it had produced no further block after height 961,633. For enforcing nodes, this is a consensus split. Bitcoin’s dominant proof-of-work chain continued advancing, leaving the two-block branch isolated.

Blocks attributed to Foundry, F2Pool, AntPool, ViaBTC and MARA all appeared on the dominant branch during the 59-block sample. Produced blocks showed no observable major-pool switch after the window opened; explorer pool attribution is coinbase-based and does not establish a formal policy.

For BIP-110, the exchange status feeds provide only a bounded check. Coinbase and Kraken reported their Bitcoin-related systems operating normally in their official status feeds, while wallets, merchants and self-hosted nodes remained outside the sample.

At the snapshot time, 1,957 blocks remained in the BIP-110 mandatory-signaling window. The zero-of-59 result establishes a clear absence of dominant-chain signaling to date while leaving the final outcome open. So far, the deadline has produced a measurable minority fork with little observed mining support, while the Coinbase and Kraken status feeds showed normal Bitcoin operations.