The controversial Bitcoin Improvement Proposal known as BIP-110 produced a chain split over the weekend — but the breakaway fork sputtered almost immediately, mining just two blocks in roughly eight hours before effectively stalling.
The underwhelming result underscores the immense practical difficulty of forcing a rule change on Bitcoin without meaningful miner support.
A Fork With No Hashpower
The split occurred after BIP-110's mandatory signaling window opened at block 961,632 on Saturday. The proposal, which would temporarily restrict non-financial data from being embedded on the Bitcoin network, entered signaling with less than 3% of miners signaling support — far below the 55% threshold required for standard activation.
Proponents had pushed BIP-110 as a user-activated soft fork (UASF), relying on node operators rather than miners to enforce the new rules. The theory: if enough nodes reject non-signaling blocks, miners will be forced to comply or risk mining blocks that the network won't accept.
In practice, the fork chain inherited Bitcoin's full mining difficulty — a parameter adjusted every 2,016 blocks based on total network hashpower. With only a tiny fraction of Bitcoin's hashpower working on the BIP-110 chain, each block took roughly four hours to find. The main Bitcoin chain, by contrast, continued producing blocks every 10 minutes as usual.
One Miner Breaks Ranks
In a notable sideshow, at least one miner rejected BIP-110 despite operating through a pool that supported it. Simple Mining, a company that runs machines through the Ocean mining pool, used the pool's software that lets individual miners choose for themselves — and went the other way.
Ocean had been backing BIP-110 by default. The defiance from a participant highlights the tension within mining pools over whether operators or individual miners should decide on protocol-level votes.
Replay Attack Warning
The fork created immediate safety concerns. Bitcoin developer warnings emphasized that holders risk losing real BTC if they attempt to sell coins from the BIP-110 minority chain.
Because both chains share the same transaction history up to the split point, signed transactions on the fork chain can theoretically be replayed on Bitcoin's mainnet. Until the chains can be reliably separated — which requires specialized replay protection — doing nothing is the safest course for ordinary holders.
The Broader Debate
BIP-110's failure to gain traction does not end the underlying debate. The proposal was motivated by concerns over inscriptions and ordinals — non-financial data embedded in Bitcoin transactions that some argue constitutes spam and creates legal liability.
Prominent figures including Michael Saylor and Adam Back have opposed the restriction, arguing that Bitcoin should remain neutral about transaction content. But the growth of inscription-based activity has put sustained pressure on block space and fees, ensuring the debate will continue regardless of BIP-110's fate.
For now, Bitcoin's mainnet continues operating normally. The BIP-110 chain may limp along at a block every several hours, but without a dramatic increase in hashpower or economic support, it is effectively inert. The UASF playbook that worked for SegWit in 2017 has not replicated — and the signaling window has four weeks remaining.