Earlier quoted context omitted.
I have generally mixed feelings about insider trading, because in the end, people making decisions on best information looks like economically profitable for the system. That said, Coinbase did more than insider trading today, they deliberately hid their BCash announcement to perform insider trading. That is straight down fraud to me. They provoked the insider trading situation.
What evidence do you have they performed insider trading? There is none. You are just speculating.
Its pretty clear something happened because there was quite a commotion hours before it happened, which means market makers knew it was coming. I have documented message sbefore the coinbase announcement that something weird was going on, and so has the community. Not only that, coinbase gave the appearance of neutrality when it deliberately lied on release date and scope of release. For what purpose but to take advantage of the information arbitrage.
Coinbase sold its users today and as a portion of the community has been vocal about, I recommend leaving coinbase to another exchange that hasn't proven to screw over their users.