I also wonder why there is a difference between the coldwallet balance and the amount of invested BTC:
2,358 / 2204
I know there is a hotwallet for instant withdrawals but I don´t think the hotwallet contains as much as 154 BTC
(and that is only the site bankroll! there are of course also lots of user balances which aren´t invested at the
moment)
At JD we kept a hot wallet for instant withdrawals, an online-but-off-site wallet, and a cold wallet.
The cold wallet is hard to withdraw from, by design, and so it's useful to keep some coins in an intermediate state - not on the site where they are at risk, but not completely cold either.
Maybe DB is using a similar scheme.
At JD user balances usually accounted for roughly 0% of the total coins we were holding. After playing, people usually would either invest their balance or withdraw it.