Ethereum Classic exists because of a decision made in July 2016, at block 1,920,000, when most of the Ethereum community chose to rewrite the chain to undo a theft and a minority chose to keep the ledger as it was. The minority kept the original transaction history and the original name. ETC is that chain. It has been running on its own ever since, with its own miners, its own monetary policy and its own record of security failures, and the reason to understand it is that the 2016 argument about immutability never really ended.
What the DAO fork actually decided
The DAO was an investor-directed fund built on Ethereum that raised more than $150 million in ETH during 2016. A flaw in its smart contract let an attacker drain roughly 3.6 million ETH into a child structure, and the funds were frozen rather than lost only because of how the exploit was written.
Faced with that, the community split. One option was a backward-incompatible change that moved the funds to a recovery contract and treated the theft as if it had not happened. The other was to accept the theft as part of the ledger's permanent record, on the argument that reversing state once establishes that state can be reversed again. The majority took the first option. The chain that resulted is the Ethereum network most people know as ETH. The chain that refused is Ethereum Classic, which kept chain identifier 61 and the pre-fork history.
The practical consequence is narrow and important. On ETC, a transaction that has been confirmed stays confirmed, including transactions that came out of an exploit. That commitment is the entire product pitch, and it is also the reason the network is small.
Both sides still defend their choice. Supporters of Ethereum Classic argue that immutability is the only property that makes a public ledger worth trusting, and that a chain which edits its own history once has announced that it can do so again. The Ethereum Foundation and the majority who forked argued that recovering stolen customer funds in an extreme case was the responsible move, and that protocol governance must be able to intervene. Neither argument has been settled by events.
The 210.7 million cap and the schedule behind it
ETC does not have Ethereum's monetary policy. It has a hard cap, adopted through the Gotham upgrade on 11 December 2017, which implemented improvement proposal ECIP-1017. The mechanism is called 5M20: every 5,000,000 blocks, the block reward falls by 20%. That schedule produces a maximum supply of roughly 210.7 million ETC.
| Era | Starts at block | Block reward | When |
|---|---|---|---|
| Era 1 | 1 | 5 ETC | July 2015 |
| Era 2 | 5,000,001 | 4 ETC | December 2017 |
| Era 3 | 10,000,001 | 3.2 ETC | March 2020 |
| Era 4 | 15,000,001 | 2.56 ETC | April 2022 |
| Era 5 | 20,000,001 | 2.048 ETC | May 2024 |
The next reduction takes the reward to 1.6384 ETC when block 25,000,000 is reached. Because the cuts are tied to block height rather than to a calendar, the date slips if hashpower leaves the network, which is a useful thing to know before quoting a projection. Read the current reward off a block explorer rather than from any article, including this one.
ETC next to ETH, in one table
The two chains share a starting point and a virtual machine, and almost nothing else. Confusing them is the most common error among new buyers, and it is a costly one, because the two assets are not interchangeable and the networks reject each other's transactions.
| Feature | Ethereum Classic (ETC) | Ethereum (ETH) |
|---|---|---|
| Chain identifier | 61 | 1 |
| Consensus | Proof of work, mined | Proof of stake since 2022 |
| Supply | Capped near 210.7 million | No hard cap |
| 2016 DAO theft | Left in the ledger | Reversed by fork |
| Development funding | Grants and donations, no treasury | Foundation and ecosystem funding |
Notice the asymmetry in funding. Ethereum Classic has to argue for every development grant it receives, which shows up in slower tooling and thinner documentation.
Proof of work, and what the Merge did to it
ETC still mines. Miners compete to solve a puzzle, the winner extends the chain and collects the reward, and the security budget is whatever they spend on electricity. When Ethereum switched to proof of stake on 15 September 2022, an enormous fleet of graphics cards lost its main customer overnight, and a large share of that capacity moved to Ethereum Classic because the mining algorithm was compatible. Block explorer data shows the network's hashrate jumping from roughly 60 TH/s to about 265 TH/s within a day, and higher still in the following week.
The 51% attack record
Any honest description of ETC has to include this, because it is the most serious thing that has happened to the network. In January 2019 an attacker rented hashpower, mined a longer private chain and released it, reorganising the ledger and double-spending roughly 219,500 ETC. August 2020 was worse: three separate attacks in a single month, with double-spends reported at about $5.6 million on 1 August, $1.68 million on 6 August, and a reorganisation of more than 7,000 blocks reported on 29 August.
The response was a defence called MESS, deployed through ECIP-1100 in September 2020, which makes deep reorganisations exponentially more expensive for an attacker. Since then, no successful attack of that kind has been reported publicly. That is a real improvement and it is not a guarantee. A proof-of-work chain with a modest security budget remains structurally cheaper to attack than a large one, which is why exchanges typically demand more confirmations for ETC deposits than for other assets. Coinbase, which was among the venues hit in 2019, published a post-mortem and temporarily paused ETC deposits on its platform.
Hashrate is not the same thing as safety either. Rented capacity on markets such as NiceHash makes an attack a purchase decision rather than a hardware project.
How thin the ecosystem is
Ethereum Classic has no company behind it and no protocol treasury. Development runs through an open improvement proposal process, with the Core-Geth client maintained with support from the ETC Cooperative, a non-profit that has been the most consistent funder of the network. Earlier organisations have come and gone, including one that shut down in 2018 for lack of funding. Draft proposals published in 2025 under the Olympia banner would route part of the transaction fee to an on-chain treasury and create a spending framework, but they remained drafts rather than active rules at the time of writing. Compare that funding position with Ethereum's before you assume the two chains differ only in price.
Thin funding has a second effect that matters to a holder. Documentation, wallet support and exchange integration all move more slowly, so the friction of simply holding and moving ETC is higher than it looks from a price chart. Confirm that the wallet and the exchange you intend to use both support the network before you need them, rather than assuming that Ethereum tooling will carry across.
Checks worth running before you touch ETC
Start with the network, not the price. ETC is EVM-compatible, so a contract address copied from Ethereum tooling may well be wrong here. Confirm the chain you are connected to before signing anything, and use a wallet that supports Ethereum Classic explicitly rather than assuming an Ethereum wallet will do.
Then check supply and issuance on a public explorer such as Blockchair or the ETC Cooperative's own explorer: the current block height, the current reward, and the distance to block 25,000,000. If someone quotes you a supply figure that ignores the 5M20 schedule, they are describing a different chain or a different year. Finally, check the venue. Exchanges handle ETC differently, with different confirmation requirements and different withdrawal paths, and the coin is old enough that fake tokens carrying the ticker exist on other networks.
None of this is a recommendation either way. It is the difference between owning a proof-of-work ledger with a documented attack history and owning a ticker because it is cheaper than the better-known chain next to it.
This article is general information, not investment advice. Network parameters change through upgrades; verify block reward, supply and upgrade status in the official ECIP repository and on a live block explorer.