Coinbase now lets you buy and sell Bitcoin Cash

Coinbase has just added full support for Bitcoin Cash (BCH) - meaning you can now send, receive, buy and sell the cryptocurrency. All users will also be credited an amount of Bitcoin Cash equal to their Bitcoin balance during the hard fork that occurred August 1st, 2017.
Bitcoin Cash trading will also be available on GDAX, Coinbase's institutional-focused exchange.
Update: As of now both Coinbase and GDAX seem to be experiencing intermittent outages andBitcoin Cash trading has been suspended, so it may take some time until traffic settles down and Bitcoin Cash is actually available for trading.
Immediately after the announcement Bitcoin's price fell as much as 25% to a low of $14,000, but seems to have stabilized around $16,600 as of writing, which is still down about 10% from a few hours ago.
Bitcoin Cash is up around 50% in the last few hours, trading around $3,300.
As a refresher, Bitcoin Cash was created when Bitcoin "forked" in early August, by a group of developers who wanted to alter Bitcoin's code so the blockchain could process more transactions at a faster speed, as well as require a much lower fee. When Bitcoin core developers disagreed, a group decided to copy and modify Bitcoin's code to create Bitcoin cash.
Originally Coinbase said they wouldn't support Bitcoin Cash - but quickly reversed course on August 3rd to say that customers would be able to withdraw it by January 1st, 2018. However they stopped of short of saying whether or not they'd provide full support and allow it to be bought and sold. So today's full addition of the digital currency comes as a surprise for anyone who follows the cryptocurrency world.
In a blog post, Coinbase said they considered " developer and community support, security, stability, market price and trading volume" when deciding to fully support the digital currency. Additionally, they gave some (brief) rational behind the decision: