Bitcoin Gold
October 2017 fork changing the mining algorithm to resist ASICs. Failed to gain lasting adoption.
Forked from Bitcoin
Bitcoin Gold (BTG) forked from Bitcoin on October 24, 2017 at block 491,407, changing the proof-of-work algorithm from SHA-256 to Equihash — the same family used by Zcash — with the stated goal of 'decentralizing' mining by making ASICs ineffective.
The project was led by Jack Liao and positioned itself as an anti-ASIC alternative during the frenzy of post-BCH forks. Unlike BCH, BTG did not emerge from the block size debate directly; it rode the wave of fork mania when anyone with a GitHub repo could spin up a Bitcoin clone and list it on exchanges.
BTG faced immediate credibility problems: a pre-mine of 100,000 coins, delayed wallet support, and multiple exchange listing controversies. Its Equihash algorithm was later ASIC-mined anyway. The chain suffered a series of 51% attacks in 2018 and 2020, with exchanges losing millions to double-spends.
Outcome
Marginal chain with low hash rate and limited developer activity. Widely regarded as a failed experiment in GPU-mining nostalgia.