Why Could Selling Forked Coins Put BTC At Risk?
Bitcoin holders could face an unusual security risk this weekend if a proposed network split produces a second chain without automatic replay protection.
If Bitcoin divides into two chains, every holder would initially have the same balance on both. That can make the new coins look like free money: a trader may offer to buy the forked version, allowing holders to sell an asset they did not previously own.
The problem is that transactions on the two chains could initially be identical. A transaction signed to send coins on the new chain could also be copied and broadcast on the main Bitcoin network. If both chains accept it, the buyer may receive not only the forked coins but the same amount of real BTC at the same address.
The process is known as a replay attack. It does not automatically empty a wallet. Only the coins included in the signed transaction would move, but those coins could leave on both chains, potentially turning what appeared to be a sale of low-value fork tokens into an unintended sale of Bitcoin.
Bitcoin developer Kevin Loaec warned that large holders could be particularly attractive targets. For users who do not understand how to separate balances safely, the simplest defense is not to transact until the two chains can be clearly distinguished. Coins that remain untouched cannot be replayed because there is no signed transaction to copy.
How Could BIP-110 Trigger A Bitcoin Split?
The potential fork centers on BIP-110, a proposal designed to restrict pictures, text and other non-payment data from Bitcoin transactions for one year.
The proposal initially sought miner support through block signalling. It requires 1,109 marked blocks within a 2,016-block period, equivalent to 55% support. Current signalling is far below that threshold, running near 2.6% as of Friday.
BIP-110 also contains a second activation mechanism. Beginning at block 961,632, expected around this weekend, computers running the software are set to reject blocks that do not carry the required signal regardless of whether miners have reached the 55% threshold.
Almost all blocks currently being produced lack that signal. That means BIP-110 nodes could begin rejecting the chain supported by most Bitcoin mining power once the activation point is reached.
A lasting fork would still require miners to continue producing blocks on the BIP-110-compatible branch. If nobody mines that chain, it could stop almost immediately. With signalling currently low, any minority branch could also advance very slowly compared with the main Bitcoin chain.
Investor Takeaway
The main risk is not simply that Bitcoin could split. It is that holders may rush to sell unfamiliar forked coins before the two balances have been safely separated, exposing real BTC to replay. Investors who do not understand the technical process may be better served by waiting.
Why Is Replay Protection Important?
Some blockchain forks deliberately change transaction rules so that a payment signed on one network cannot be accepted on the other. That mechanism, known as replay protection, allows holders to spend assets on each chain independently.
The possible BIP-110 fork would not initially provide that separation. Its restrictions on transaction data are not scheduled to begin until block 965,664, expected around the beginning of September.
Until then, users seeking to sell coins from a minority branch would need to create or obtain coins that exist only on one chain and use them to separate the balances before making a transaction. That process requires technical care, particularly for users unfamiliar with coin control and chain-specific transactions.
The absence of automatic replay protection also creates an opportunity for buyers. A counterparty could offer an unusually attractive price for the new token precisely because obtaining the signed transaction may provide an opportunity to replay it on Bitcoin.
What Should Bitcoin Holders Watch This Weekend?
The first question is whether a viable second chain appears at all. BIP-110 nodes rejecting the dominant chain does not guarantee that miners will continue producing blocks on the alternative branch.
Investors should therefore watch block production after 961,632, miner participation on any competing chain and whether exchanges or wallet providers announce support for a forked asset. A token appearing in a wallet does not by itself mean that it has durable value or sufficient liquidity to justify moving it immediately.
Timing is also approximate because Bitcoin blocks do not arrive at fixed ten-minute intervals. The activation point could be reached earlier or later than current estimates.
For holders, the risk-reward calculation is asymmetric. The forked asset may ultimately be worth little or nothing, while an incorrectly handled transaction could move valuable BTC on the main chain. Until replay protection or reliable balance-separation methods are established, avoiding transactions involving the new chain may be the safer approach.