Deliveroo shares tanked when they started trading. It's normal to see shares go down after they've had the IPO. COIN shares aren't staying down for long.
I was expecting, at least at start, to have unrealistic price for Coinbase shares. Also, as bad luck/bad timing, Bitcoin price has also dropped and some think that they're related, hence may selling/not buying the shares.
All in all, with Bitcoin still expected to be in the middle of bull run, bitcoiners have no reason to buy Coinbase shares.
And yeah, the insiders know all this, hence they thought they'll make a quick buck.