A breakaway Bitcoin chain built around the contentious BIP-110 proposal has ground to a near-standstill just hours after splitting from the main network. The split occurred at block 961,632 on Saturday, when nodes running BIP-110 began rejecting any block that didn't signal support for the proposal. Roughly eight hours later, the fork chain had produced only two blocks, reaching block 961,633, while the main Bitcoin chain had already advanced to block 961,681 — a 48-block gap representing about a day's worth of normal network activity.
The first block to withhold BIP-110 signaling was mined by AntPool, one of Bitcoin's largest mining pools, triggering the split. The alternative, BIP-110-signaling block that anchors the new minority chain was produced by a miner using Ocean. Both are established mining pools that combine hashpower from many individual operators, but only a sliver of that combined hashpower ended up backing the fork.
Support for BIP-110 never came close to the threshold needed to avoid a split. Just 2.53% of blocks signaled backing for the proposal over the two weeks leading into activation, far short of the 55% required for a clean, network-wide change. That left BIP-110 supporters with the option taken this weekend: break off and mine their own chain rather than abandon the proposal.
Why the Fork Chain Is Barely Moving
The breakaway chain's biggest problem is structural. It inherited Bitcoin's existing mining difficulty setting in full, despite controlling only a tiny fraction of the network's total hashpower. That mismatch means blocks are arriving every few hours instead of the roughly ten minutes Bitcoin is tuned for. The chain cannot recalibrate its difficulty until it completes 2,016 blocks, a milestone Bitcoin's full hashpower reaches in about 14 days but that, at the fork's current pace, is projected to take roughly 350 days.
Related: BIP-110 Enters Mandatory Signaling as Miner Support Stays Below 3%
There's also a security dimension. Because both chains continue to accept identical transactions, they remain vulnerable to replay attacks, in which a transaction broadcast on one chain can be rebroadcast on the other without the sender's consent. Anyone holding or trading the fork's coins faces that exposure, compounded by confirmation times that stretch for hours on the minority chain.
Opposition From Bitcoin's Most Prominent Voices
BIP-110 arrived with vocal opposition from some of Bitcoin's most recognizable figures well before Saturday's split. Strategy chairman Michael Saylor argued the proposal solves a problem that doesn't warrant the risk it introduces, warning in a statement reported by CoinDesk that it would turn a narrow dispute over spam into a full consensus change:
"There are 110 things more dangerous to Bitcoin than spam. BIP 110 turns a spam dispute into a consensus change that would invalidate some currently valid, fee-paying transactions."
Blockstream CEO Adam Back was similarly blunt, telling supporters of the proposal that the network was not going to bend to their preferences and that any resulting fork would stand apart from Bitcoin itself. Miner signaling for BIP-110 never exceeded roughly 1% in the run-up to the split and had fallen to zero by early August, while node-level support stayed in the low single digits, carried almost entirely by users running the Bitcoin Knots software rather than Bitcoin Core.
A Narrow Window Still Ticking
The mandatory signaling window tied to BIP-110 doesn't close until block 963,647, and technically remains open. But at the fork chain's current output of roughly one block every several hours, it has no realistic path to reaching that target before the window lapses. For now, BIP-110 looks set to remain what its own signaling data suggested for months: a minority position that produced a slow-moving side chain rather than a change to Bitcoin itself, a trajectory tracked closely as support stalled below 3% in the weeks before activation.
