What happens if Bitcoin splits?

If bitcoin splits, the network divides into two chains that agree on every block up to a certain height and disagree after it. Every coin that existed before the split now exists on both chains, controlled by the same private keys. What happens next depends on how many miners, node operators, exchanges and users follow each side.

Why would a bitcoin chain split happen?

A split happens when some participants enforce rules that others reject. The usual case is a contested hard fork, where new rules allow blocks that old software refuses.

A soft fork can split the chain too, if a minority enforces it on its own. BIP 110, a proposal to restrict data-heavy transactions for about a year, required blocks in a set window to signal support and told its nodes to reject any block that did not. Only about 2.5% of blocks signaled, against a 55% threshold, crypto.news reported. When the window opened at block 961,632 on August 8, 2026, a BIP 110 supporter mined a competing version of that block, Bitcoin.com News reported, and the chain split.

What happens to your bitcoin after a split?

Your coins are not moved or lost. The same keys unlock the same balance on both chains. If you hold keys yourself, your wallet software decides which chain it follows. If an exchange holds your coins, the exchange decides.

Exchanges set their own policy. Before the 2017 Bitcoin Cash split, BitMEX said it would decide alone whether to support any forked coin, would not distribute Bitcoin Cash, and told customers who wanted it to withdraw beforehand. For the BIP 110 chain, crypto.news reported that no exchange had listed it as a separate coin as of August 10, 2026.

What is replay protection and why does it matter?

Replay protection makes a transaction valid on only one chain. Without it, a payment you send on one chain can be copied and broadcast on the other, spending coins you meant to keep. BitMEX's 2017 policy called for strong two-way replay protection enabled by default. Bitcoin Cash later made a new signature format, SIGHASH_FORKID, mandatory, according to Bitcoin Cash Node documentation. The BIP 110 chain had none, which crypto.news called a significant oversight, though it reported no confirmed losses.

How do bitcoin hard fork coins survive?

A new chain needs hashrate. With about 0.15% of mining power, the BIP 110 chain produced two blocks over roughly eight hours and then stalled, crypto.news reported, with its next difficulty adjustment estimated about 350 days away. The BIP 110 document is now marked closed. Bitcoin Cash, by contrast, has kept running since 2017, as explained in bitcoin vs bitcoin cash. In the US, new coins received from a fork can be taxable, covered in are hard forks taxable.