Bitcoin Cash was created by a fork on August 1st, 2017. All customers who held a Bitcoin balance on Coinbase at the time of the fork will now see an equal balance of Bitcoin Cash available in their Coinbase account. Your Bitcoin Cash balance will reflect your Bitcoin balance at the time of the Bitcoin Cash Fork, which occurred at 13:20 UTC, August 1, 2017.
Bitcoin Cash sends and receives are functional. Buys and sells on the Coinbase website and in our mobile apps will be available to all customers once there is sufficient liquidity on GDAX. We anticipate that this will happen tomorrow.