After FTX bankruptcy, it feels like the exchanges have to be transparent with their hold and cold wallet amount. I got an e-mail from KuCoin revealing their value in the wallet(although it's not all) but it gives me an insight at least about how is that exchange going to manage the currency in the future. But still, it's not recommended to store money in online wallet even though it's just a small amount, you are not controlling your own money if you put it there.