My biggest win was at Bitstarz Casino 3 or 4 years ago.
I deposited 0.2 BTC and won 11BTC.
The BTC price at this time was arround 450$.
I played in the following weeks and months at the same casino and lost all of my winnings.

That's pretty bad, and I know it happens sometimes when we are thinking that we could win more and make a triple win.
I have that experience mate but not totally I gamble them all, I used only the money which I used to gamble at first and kept my winnings. This what I feel to be secured and if ever I lose, they can't take away all my money...