“cold storage”
What the heck is that? Did they copy the keys and wallets onto a usb drive?
Actually, anybody storing their crypto on an exchange is just waiting for somebody to steal it. It should be treated like gold locked up in a vault (your own) - don’t let anybody have access to it unless or until it is being converted/moved into something else like good old foldable cash.
look at ledger.com for an example of an offline wallet