Bitcoin Cash (BCH)


Year	2017
Type	Hard fork (permanent chain split)
Status	Separate chain (not Bitcoin)

What it is

Bitcoin Cash is a hard fork that split from Bitcoin at block 478,558 on August 1, 2017. It increased the block size limit from 1 MB to 8 MB (later 32 MB). Despite using “Bitcoin” in its name, BCH is a separate cryptocurrency with its own chain, rules, and diminishing network effects.

Why it happened

The “block size debate” dominated Bitcoin development from 2015-2017. A faction argued that Bitcoin needed larger blocks to scale on-chain. The Bitcoin community chose SegWit and layer-2 scaling (Lightning Network) instead. The large-block faction forked off rather than accept the community’s decision.

Why it is not Bitcoin

Nakamoto consensus rejected it. The Bitcoin chain (with SegWit) retained the overwhelming majority of hashrate, nodes, users, and economic activity.
Market verdict is clear. BCH trades at a fraction of Bitcoin’s price, reflecting the market’s assessment that it is not the real Bitcoin.
Name confusion is deliberate. Using “Bitcoin” in the name has been a persistent source of confusion for newcomers, which critics argue is by design. The “Bitcoin.com” domain was used to promote BCH over Bitcoin for years.
Removed proven upgrades. BCH stripped out SegWit, losing the malleability fix, the capacity increase via witness discount, and the upgrade path that enabled Taproot.
Fragmented further. BCH itself split into Bitcoin SV in 2018, demonstrating the instability of contentious hard forks.

Key details

Forked at block 478,558 (August 1, 2017)
Initial block size: 8 MB (later increased to 32 MB)
All Bitcoin holders at the fork received equal BCH
Removed SegWit and Replace-By-Fee (RBF)
Emergency Difficulty Adjustment (EDA) caused erratic block times in the early months

Lesson for Bitcoin

Bitcoin Cash demonstrated that hard forks without overwhelming consensus create permanent splits, not upgrades. The market and the network chose the original chain. This is Nakamoto consensus in action: the chain with the most accumulated work, the most nodes, and the most economic activity is Bitcoin.