Following Bitfinex's lead, Coinbase takes a similar stance defining BTC:
Timeline and Support — Bitcoin Segwit2x and Bitcoin GoldWe wanted to give customers another update on two upcoming Bitcoin forks — Bitcoin Segwit2x and Bitcoin Gold. You can read more about what a digital currency fork is here.
We operate by the principle that our customers should benefit to the greatest extent possible from hard forks or other unexpected events. This is essential in our mission to make Coinbase the most trusted, safe, and easy-to-use digital currency exchange.
Bitcoin Segwit2xThe Bitcoin Segwit2x fork is projected to take place on November 16th and will temporarily result in two bitcoin blockchains. Following the fork, Coinbase will continue referring to the current bitcoin blockchain as Bitcoin (BTC) and the forked blockchain as Bitcoin2x (B2X).
Any customer with a BTC balance on Coinbase at the time of the fork will be credited with an equal amount of the B2X asset on the Bitcoin2x blockchain. No action is required — we will automatically credit your account. So, if you have 5 BTC stored on Coinbase before the fork; you will have 5 BTC and 5 B2X following the event.
For more information about Bitcoin2x please see our FAQ page.
Bitcoin2x TimelineApproximately 24 hours pre-fork. Coinbase will temporarily disable all bitcoin buy, sells, sends and receives. ETH and LTC will not be impacted. You will still be able to see your Bitcoin balances and monitor the price. If you plan on moving BTC into your Coinbase account, we highly recommend that you do so at least 24 hours before the fork to ensure your transfers are confirmed.
Fork (block 494,784). Any Coinbase customer with a confirmed Bitcoin balance at this point will be credited an equal amount of Bitcoin2x.
Within 24 hours post fork. Coinbase customers will be able to buy and sell both Bitcoin and Bitcoin2x. When you visit Coinbase.com or open your Coinbase app, you will see your new Bitcoin2x balance (in Accounts).
Approximately 24–48 hours post fork. Once we have ensured that the blockchains are stable, Coinbase will re-enable Bitcoin and Bitcoin2x sends and receives. Please be careful when sending funds as certain wallets and bitcoin services may refer to the two blockchains differently.
Bitcoin GoldThe Bitcoin Gold fork is projected to take place on October 23rd. Information about this fork has been limited and there are concerns about its security and stability. As a result, we do not believe it is safe to allow support for Bitcoin Gold at this time. If the blockchain proves to be secure and valuable, Coinbase may choose to support it. At that point, your account will be credited with an amount of Bitcoin Gold equal to your Bitcoin (BTC) balance at the time of the fork.
You can read more about Bitcoin Gold at our FAQ page.
Over the coming weeks, we will keep you updated on this event through our blog, status page and twitter.
https://blog.coinbase.com/timeline-and-support-bitcoin-segwit2x-and-bitcoin-gold-eda72525efd
