Bitcoin BIP-110 enters mandatory phase, with support rate of 2.53%

Bitcoin's controversial BIP-110 testing has moved from the signaling stage to actual chain splitting, with the first few hours showing miners overwhelmingly continuing to build on the existing Bitcoin chain.

Summary

When BIP-110 entered the mandatory signaling phase, only 51 of the first 2016 blocks supported the proposal. The execution fork stalled at a block height of 961,633, while the Bitcoin main chain reached 961,731 on Sunday. The forced signal phase will continue until block 963, 647, and the lock time will be no later than block 963, 648. The proof-of-work change is a backup code, and Chris Guida stated that no activation date has been set. Holders still face replay risk because transactions may be valid on both chains without separation.

The proposal entered the mandatory signaling phase of Block 961,632 on August 8. Previously, only 51 of the first 2016 blocks (accounting for 2.53%) expressed support. Nodes executing BIP-110 then began rejecting blocks without version bit 4. The latest available BIP-110 monitoring data on August 9 showed that the execution fork stalled at block 961,633 after only producing two blocks. Bitcoin's non-execution chain has reached 961,731, leading by 98 blocks. The tracker also showed that there was no BIP-110 signal in the first 100 blocks of the new difficulty cycle of the dominant chain.

"Only 2.6% of miners signaled that BIP-110 failed to gain widespread support among miners. In blocks 961, 632, its node will reject non-signalized blocks. BIP-110 will stall or fork to irrelevant, while Bitcoin will operate normally. Bitcoin works as designed."-- Michael Saylor, August 8, 2026

Bitcoin BIP-110 fork expands after continued low support among miners

Splitting occurs because BIP-110 applies different validity rules during its mandatory signaling window. According to the official BIP-110 specification, execution nodes must reject any block with a height between 961,632 and 963,647 that is not marked with bit 4. Ordinary Bitcoin nodes do not impose this requirement, so they can continue to follow non-signal blocks.

Roughnecks, an anonymous miner organization using OCEAN's DATUM system, produced BIP-110 blocks 961,632 and 961,633. Subsequently, the fork did not advance for approximately 15 hours in the latest monitoring snapshot. Early Sunday, when the main chain was at 961,721, the gap had widened to 88 blocks.

The widening gap reflects differences in computing power allocated to each chain. BIP-110 enters the current cycle with the same mining difficulty environment, but its execution fork only has a small portion of Bitcoin's computing power. If no more miners join, it must continue to slowly find more difficult blocks until the next difficulty adjustment. This does not technically erase the minority fork. There may still be more computing power turning to it. However, currently observed block production does not provide evidence that enough miners are switching to make up for the cumulative workload gap.

The 55% voluntary threshold was significantly missed

BIP-110 allows early locking when 1109 (or 55%) of the 2016 blocks indicate support during the difficulty cycle. According to monitoring data, only 51 signals were recorded in the cycle as of Block 961,631, with a support rate of only 2.53%. Strategy Executive Chairman Michael Saylor had pointed out before the deadline that the low signal rate suggested the proposal lacked broad support from miners. He called the data a "non-miners consensus" based on assessments of signal numbers rather than formal network governance decisions.

Saylor and Blockstream CEO Adam Back oppose the proposal for broader reasons. Back warned that enforcing new consensus limits without broad consensus could divide participants, while supporters argued that the limits were necessary to prevent the use of non-monetary data. These are still competing views on how Bitcoin's block space should be governed.

Once fully activated, BIP-110 will temporarily restrict several transaction structures. Most new output scripts will be limited to 34 bytes, OP_RETURN output to 83 bytes, and some data push and witness elements to 256 bytes. It would also restrict certain elements of Taproot, which is valid for about a year.

Chain splitting also poses practical problems for holders

Before the mandatory signal began, Bitcoin developer Kevin Loaec warned that signed transactions could be identified by both chains because BIP-110 would not automatically separate a user's pre-fork balance. Therefore, holders who try to transfer coins on minority forks may face the risk of transferring the corresponding BTC if the same transaction is valid on the dominant chain and is rebroadcast. This risk applies to the transaction inputs involved, rather than letting the other party control the entire wallet. Keeping the coin intact before the fork avoids transactions that may be replayed. The actual risk depends in part on whether markets, wallets or exchanges begin to view minority forks as an asset worth trading. Since only two blocks have been dug up so far, there is little evidence that such an ecosystem has developed.

Proof-of-work changes remain an alternative rather than a scheduled fork

Some BIP-110 supporters have braced for the possibility that existing Bitcoin miners will continue to effectively reject the proposal. On August 1, developer Chris Guida re-based code changes based on an experimental proof-of-work code, originally written in part by Bitcoin Knots maintainer Luke Dashjr. GitHub compared 12 commits from 19 files, including code for selecting different proof-of-work algorithms. However, the code does not establish predetermined network changes. Guida described it as "just code that we kept as a backup" and said no activation deadline had been set. His comments made the proof-of-work proposal an alternative rather than an announced hard fork with a fixed date.

Dashjr continued to support BIP-110 despite criticism and rejected earlier calls to withdraw the proposal. Proponents argue that temporary restrictions will reduce arbitrary data storage, while critics tend to leave block space allocation to fees and single-node strategies.

What happens next for BIP-110

The next protocol checkpoint is defined by the block height, not a fixed date. Force signal continues to block 963,647. According to the BIP specification, the deployment reaches the LOCKED_IN state at the latest at block 963,648, and then reaches the ACTIVE state at 965,664. Only then will the proposal's reduced data transaction rules take effect. These heights can be reached on very different timelines on the two branches. The bitcoin-dominated chain continues to produce blocks at its normal speed, while the BIP-110 execution fork requires a lot of additional computing power to approach the same speed. In the latest snapshot taken, it is still 98 blocks behind after leading its replacement block by 961,632 only once.

Therefore, the next direct indicator to focus on is not another scheduled vote, but mining activity. If miners start extending the BIP-110 fork, their block production may resume. If computing power is still concentrated on the existing Bitcoin chain, the gap will continue to widen, execution fork will face an increasingly difficult path, and it will be difficult to become the chain with the most cumulative workload proof.