Of course there was insider trading done with bitcoin cash and coinbase. But in an unregulated market is that illegal? This is one of the things that makes the crypto currency market risky. Morally of course it is wrong.

In regards to coinbase I'm still a little upset about the visa debacle from Feb., Not sure if it is quite cleared up on my card yet and if it is I've lost some money. Visa says those transactions incur a "Cash Advance fee" still looking into this, but yes Coinbase is not looking too favourable in my books right now.
If they want to be a leader in the crypto world they need to clean up their stuff so that they can be trusted.
Just quickly reviewing their blog about that Visa thing I see lots of unhappy people posting
https://blog.coinbase.com/joint-statement-from-visa-and-worldpay-for-coinbase-customers-9a6f2ff5f3b3

If anyone has some more info, that applies to my case by all means feel free to share it with me. Thanks!