Expect a rally, Coinbase just reversed it's decision to support bitcoin cash.

"...Over the last several days, we’ve examined all of the relevant issues and have decided to work on adding support for bitcoin cash for Coinbase customers. We made this decision based on factors such as the security of the network, customer demand, trading volumes, and regulatory considerations.

We are planning to have support for bitcoin cash by January 1, 2018, assuming no additional risks emerge during that time.

Once supported, customers will be able to withdraw bitcoin cash. We'll make a determination at a later date about adding trading support. In the meantime, customer bitcoin cash will remain safely stored on Coinbase."