The eCash fork splits bitcoin at block 973,728 today

Bitcoin gets a new chain today at block 973,728, and every address holding BTC at that moment is credited with 1 ECX per coin. The BTC stays where it is. Block 973,666 arrived at 08:34 UTC with 62 blocks still to mine, and the last 200 blocks averaged 10.13 minutes, which puts the split close to 19:00 UTC. The project's own page was showing 16:07 UTC, so plan for the evening rather than the afternoon.

“no claim, no form, no snapshot registration”

— eCash.com, operated by Blockchain Emulation Services Ltd, on how ECX reaches holders, https://ecash.com/

Holding your own keys at the snapshot is the whole eligibility test. Coins on an exchange belong to the exchange at that moment, so its policy decides whether you see anything. CoinW said it will credit eligible balances 1:1 without committing to trading, deposits or withdrawals. bitFlyer said it has no plans to list ECX or credit it. Coincheck said the same on 9 October.

Replay protection comes down to one number

A transaction you sign after the split can be valid on both chains, which is how you lose the coin you meant to keep. The eCash splitting page sets the marker at locktime 499,999,998, and it asks for at least one input with a sequence below 0xffffffff, because bitcoin ignores locktime when every input is final. The sharpest instruction on the page is a prohibition: do not use 500,000,000. That is the threshold where bitcoin stops reading locktime as a block height and starts reading it as a Unix timestamp, so the marker sits two below the border. Changing the destination address does nothing against replay, and if you have already moved BTC since the snapshot, check both chains rather than assume the ECX stayed behind.

Three dates, all on the same grid

• alpha: block 963,648, 23 August
• beta: block 967,680, 19 September
• mainnet: block 973,728, today

Each of those heights divides by 2,016, the number of blocks in a difficulty period. They are the 478th, 480th and 483rd retargets, spaced two periods and then three periods apart, which is why the project describes the launch as tied to the next difficulty adjustment rather than to a date. Our July piece on this fork expected it on 21 August. The split lands 69 days after that.

The 1:1 ratio also means the project does not set its own supply. By block 973,728 bitcoin has issued 20,105,400 coins under its schedule, so that is the ECX credited at the snapshot, minus whatever miners never claimed. The fork activates BIP300 and BIP301, Paul Sztorc's drivechain and blind merged mining proposals, which let opt-in sidechains hang off the main chain. One more thing to keep straight: this ECX has nothing to do with eCash XEC, the older project that shares the name.

What to do today takes ten minutes. Confirm you hold the keys to the BTC you care about and read your wallet's splitting procedure before you sign anything. If the coins sit on an exchange, ask it rather than guess. The fork changes nothing about your bitcoin, and whether ECX trades for anything is a question the market answers later. BIP-110 tried to fork bitcoin in August and ended with almost no hashrate behind it.

Informational material, not investment advice. Block heights, the 1:1 ratio and the replay-protection values come from eCash.com and its splitting page, exchange policies from TokenPost. The block-pace estimate, the retarget arithmetic and the issuance figure are ours, and a block-height trigger means the time can move.