Coin columns · Mainnet Province
Ethereum Classic (ETC): The Original Chain That Rejected the DAO Fork
‘Code is law’ and a supply capped near 210.7 million
Ethereum Classic is the blockchain that kept the original Ethereum ledger running after the 2016 hard fork that reversed a major hack. It still uses proof of work, even though Ethereum itself moved to proof of stake.
1. How the split happened
In June 2016 an attacker exploited a flaw in The DAO, an investment fund built on Ethereum, and drained about 3.6 million ETH. Most of the community backed a hard fork, a rule change that splits the chain, at block 1,920,000 on July 20 to return the funds; that chain is today’s Ethereum.
Those who held that recorded transactions must never be altered, summed up as ‘code is law’, kept the old chain running as Ethereum Classic. No company or foundation owns it; supporters such as the ETC Cooperative and independent developers maintain it. On the Crypto Nation map, ETC is the city-hall tower of its own district in the Mainnet Province, as the native coin of an independent mainnet.
2. How it works
ETC runs the Ethereum Virtual Machine, the environment that executes smart contracts, so most Ethereum contracts and tools work with little change. Blocks are mined by proof of work, and since the 2020 Thanos upgrade ETC has used Etchash, a variant with a smaller mining dataset.
Its monetary policy, ECIP-1017, adopted in 2017, cuts the block reward by 20% every five million blocks, limiting total supply to roughly 210.7 million ETC. The ‘difficulty bomb’, which made mining steadily harder to push Ethereum toward upgrades, was removed from ETC.
3. Milestones
When Ethereum ended proof of work with the Merge in September 2022, some of its GPU miners moved to ETC and its hashrate jumped. ETC became the best-known proof-of-work chain in the Ethereum family.
ETC has gone through several hard forks to stay compatible with Ethereum. Upgrades such as Atlantis in 2019 and Agharta and Phoenix in 2020 brought in major Ethereum features, and it has kept adopting selected features since.
4. Things to know
Proof-of-work chains can suffer ‘51% attacks’, in which someone with most of the mining power rewrites recent history. ETC was hit in January 2019 and August 2020, causing double-spend losses, and some exchanges then required far more confirmations for ETC deposits.
Its developer community and ecosystem are much smaller than Ethereum’s, which shows in the pace of upgrades and the range of apps. Stable development funding is a long-running challenge, and as block rewards shrink step by step, whether enough mining power will secure the network remains an open question.
Written from information public up to October 2026. It does not recommend or rate any coin and is not investment advice. If something is wrong, please tell us through the contact page.