Have you read this? https://blog.coinbase.com/update-on-bitcoin-cash-8a67a7e8dbdf
The important bit is this:
"We are planning to have support for bitcoin cash by January 1, 2018, assuming no additional risks emerge during that time."
Most likely on New Years Day, if Bcash is still around, those holding Bcash have a decision to make: will this event mean something positive or negative to them?
For those unfamiliar with this forking scenario, those who are getting this new coin and wonder 'where is this coming from?' They will find out this was freely distributed because of their pre-August 1st balances. There are plenty who will get excited and either 1. sell it all and maybe buy more Bitcoin (because they don't know what Bcash is) or 2. keep it or 3. buy more because there might be a market surge and plenty will have FOMO over this.
Regardless, I am holding the Bcash for this event. Free coin is just free coin, even if it has a market value now. My investment is in Bitcoin, not Bcash.
This is just Coinbase. Think about other places that have Bcash balances. For example, we can think of GBTC. https://finance.yahoo.com/news/grayscale-investments-llc-statement-regarding-203000163.html. According to Yahoo finance, the current market cap is $807.07M. According to the press release, they say they might plan to liquidate all Bcash and distribute the proceeds:
"The Sponsor currently expects to cause the Trust to liquidate any Bitcoin Cash associated with the Bitcoin held by the Trust and to cause the proceeds of such liquidation to be distributed on a pro rata basis to holders of units of the Trust. It is expected that any such distribution would be made only after allowing time for evaluation of the market for Bitcoin Cash and consideration of the manner in which to liquidate such Bitcoin Cash, which may be months after the fork occurs. As part of the evaluation of the market for Bitcoin Cash, the Sponsor expects to consider, among other factors, whether there are any appropriately regulated exchanges that have listed Bitcoin Cash. In addition, such distribution, if and when made, would be to owners who held Trust units on a specified record date, which is anticipated to be the day the fork occurs. The amount of any distribution will be net of expenses of the Sponsor and the Trust, including costs associated with liquidation and distribution."
Hey, this is just two cases. There is so much locked up Bcash now that this market is going to be interesting going into the next few months.
Anyway, I bet my opinion will change, but this is what it looks like now. But the Coinbase scenario is going to be interesting.