Bitcoin Hard Forks

A hard fork is a protocol change that older software will not accept, which splits the network permanently into two incompatible chains. Bitcoin has been through this repeatedly — most visibly with Bitcoin Cash in 2017 and the wave of forks that followed — usually over disagreements about block size, mining algorithms or governance.

For holders, a fork has direct practical consequences. Coins held at the snapshot block typically exist on both chains, which sounds like free money and often is not: claiming forked coins carelessly can expose your private keys, many fork tokens have no meaningful liquidity, and the tax treatment of a fork distribution is unfavourable in several jurisdictions.

This section covers the notable Bitcoin forks, what each one changed technically, whether the resulting chain retained any real hash rate and development activity, and how to evaluate a fork announcement rather than react to it.