Not really sure how to react to this, let alone if they find out that it is true, what effect this will take on coinbase.com let alone bitcoin cash value. Could be very interesting to see what comes from it if they do follow through with an investigation.
This also could just be some news companies trying to get a good story out of this and hurt bitcoin cash and coinbase.com to make people give up on the cyrptocurrency that is expanding ever so rapidly. Like a previous article I posted said, a bunch of "experts" and newspapers and reports tried to say bitcoin is going to pop in the upcomming months, and came to a group consensus that since ignoring bitcoin wasn't working, they are trying to say its just a fad, now saying insider trading is going on could be another tactic they are trying to hurt it.
https://www.theverge.com/2017/12/20/16800940/coinbase-bitcoin-cash-fork-insider-trading-probe