Bitcoin’s BIP-110 supporters split onto minority chain as main network pulls ahead

Bitcoin's (BTC) blockchain split into two branches Saturday when nodes running BIP-110 began rejecting blocks that did not signal support for the controversial "anti-spam" proposal. However, only a small minority of miners supports the forked chain. 

BIP-110 is a proposed one-year rule that would restrict non-financial data on the Bitcoin blockchain, such as Ordinals inscriptions. The proposal has transformed a technical dispute into a broader fight over who gets to decide how Bitcoin’s limited block space can be used.

The split began at block 961,632, opening a two-week period during which BIP-110 nodes will require every new block on the forked chain to signal support. Leading BTC pool AntPool mined the first block without that signal. Though most of the Bitcoin network accepted the block, BIP-110 nodes rejected it, later following an alternative block produced through Ocean by Roughnecks. 

As of 6:00 p.m. ET, Bitcoin’s main chain had reached block 961,640. The BIP-110 chain stood at block 961,633 after producing its second block, leaving it seven blocks behind.

The competing blocks at height 961,632 both build on block 961,631 but contain different sets of transactions. AntPool mined the block followed by the main network. The fork-tracking Mempool Guide attributes the alternative block to Roughnecks, a miner using Ocean.

The main chain’s early lead suggests that BIP-110's supporters have separated from the rest of the network without attracting enough mining power to keep their forked chain moving at Bitcoin’s normal pace.

Bitcoin traded around $65,000 at the time of publication, with no obvious price change following the split, according to The Block’s Bitcoin Price page.

BIP-110 sees little miner support

Bitcoin upgrades typically become adopted and lock in after a quorum of miners signal that they are ready to enforce new rules. BIP-110 set that threshold at 55%, or 1,109 of the 2,016 blocks mined during a roughly two-week period.

The proposal, however, has yet to come close to that level of support. During the final period before Saturday’s split, just 51 blocks signaled support, equal to 2.53% of the 2,016 blocks in the period, according to the BIP-110 monitor.

None of the first nine blocks on the main chain following the split signaled for BIP-110 as of publication. Once BIP-110 nodes rejected the main chain block at height 961,632, they could no longer follow any later block built on top of it. Their separate chain now needs its own miners to produce signaling blocks and extend the branch. 

BIP-110’s restrictions on transaction data will only lock in if the BIP-110 chain reaches block 963,648. Its new rules would begin at block 965,664 and remain in place for 52,416 blocks, or about one year, per the BIP-110 specification.

BIP-110's rules limit several ways of storing non-financial data in Bitcoin transactions. Among other changes, BIP-110 caps certain data fields at 256 bytes, imposes an 83-byte limit on OP_RETURN outputs, and restricts some Taproot functions. 

Whether the new chain survives will depend on whether miners continue to support BIP-110, and whether it acquires economic relevance will depend on adoption by exchanges, wallets, and other infrastructure providers. BIP-110 does not itself create a separately traded asset.

A policy dispute becomes a chain split

The BIP-110 proposal emerged from a long-running disagreement among Bitcoin developers and community members over whether the world's most valuable blockchain should also accommodate non-financial data, including Ordinals inscriptions.

As The Block previously reported, Bitcoin Core developers changed the software’s default OP_RETURN policy in its Oct. 2025 v30 update to effectively remove its longstanding 83-byte limit. That change affected which transactions Bitcoin Core nodes would normally relay to miners. 

Supporters of the change said it brought Bitcoin Core’s defaults in line with the actual behavior of miners, which were often willing to include the high-fee transactions. They also argued that users blocked from using OP_RETURN could still store data through other methods that could place a greater burden on the network. One developer earlier this year challenged BIP-110's core claims by embedding an image on the blockchain without using OP_RETURN, Taproot, or OP_IF. 

Opponents of Bitcoin Core's change said it encouraged spam on the blockchain that detracted from Bitcoin's original design, and could even enable the storage of illegal or illicit material. That dispute produced BIP-444, an October 2025 proposal to restrict arbitrary data through consensus rules rather than optional relay settings. BIP-444 later grew into BIP-110 and adopted the current activation schedule.

BIP-110's supporters, including Ocean CTO Luke Dashjr, argue that permanent data storage burdens node operators, competes with monetary transactions, and distracts developers from improving Bitcoin's core monetary functions. Critics of the proposal say Bitcoin should remain neutral toward any valid transaction that pays the required fee, regardless of how its block space is used.

Strategy Executive Chairman Michael Saylor joined the opposition in July with a 110-point essay arguing that consensus rules should address demonstrated security threats, not the perceived purpose of transactions.

"Bitcoin does not need guardians of purity," Saylor wrote. "It needs guardians of neutrality."

The rollout contrasts sharply with Bitcoin’s last major soft fork. Bitcoin's Taproot upgrade secured broad miner support before locking in and activated at block 709,632 in November 2021 without leaving a persistent minority chain.

BIP-110 thus entered its mandatory phase with negligible miner support. For now, the result is a one-block minority fork that has already fallen behind Bitcoin’s main chain.