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Bitcoin holders risk losing real BTC if they sell coins from BIP-110 fork, says developer
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- DeepHorus
Bitcoin holders risk losing real BTC this weekend if they attempt to sell coins from a potential BIP-110 fork, according to developers. A planned chain split could create duplicate balances on two chains, but selling the newly created forked coins might trigger a replay attack that also spends the seller’s actual bitcoin on the main blockchain. The warning comes as the bitcoin network approaches block 961,632, expected in the coming days, when nodes running BIP-110 software will begin rejecting blocks that do not carry a specific miner mark.
The turmoil stems from BIP-110, a proposal designed to keep pictures, text, and other non-payment data out of bitcoin transactions for a year. Under the proposal’s rules, miners must signal support by marking the blocks they produce, and the threshold is set at 55% of a 2,016-block stretch, or 1,109 marked blocks. However, current miner signalling is running near 2.6% as of Friday, far below the required level, making a miner-agreed fork unlikely through that route. Yet BIP-110 includes a second mechanism: from block 961,632, computers running the software will reject any unmarked block regardless of miner agreement.
Because nearly all blocks being mined right now lack the mark, BIP-110-compatible nodes could start rejecting the main chain, potentially creating a minority branch if some miners continue building an alternative version. Such an imbalance makes a split possible rather than certain, as a minority chain with such low support could produce blocks very slowly or stall entirely. If a split does emerge, every bitcoin holder initially holds the same balance on both chains, with the second copy potentially worth little or nothing. Somebody might still offer to buy these forked coins, presenting what looks like a free-money opportunity.
The danger lies in replay attacks, where both chains initially accept identical transactions. A transaction signed to send forked coins can be broadcast on the main bitcoin network, meaning the buyer receives the same amount in actual BTC at the same destination while the seller loses real bitcoin. Developers warn that without built-in replay protection at least until early September, the safest course for non-experts is to leave coins untouched during the potential split.
Bitcoin developer Kevin Loaec flagged the risk on X this week, stating that large holders could be targeted first. He emphasized that doing nothing is a safer option, as coins that never move cannot be replayed because there is no signed transaction to copy. His advice echoes broader concerns in the developer community about protecting inexperienced users from inadvertently losing funds.
Until replay protection is implemented or the chains are fully separated, bitcoin holders should avoid any transaction involving forked coins. The situation remains fluid, and the emergence of a minority chain depends on whether any miners choose to build on BIP-110-compatible blocks. For now, the safest strategy is to monitor developments and refrain from moving bitcoin until the network stabilizes.
