you can grow your bitcoins through multiple ways, if you invest your bitcoin in gambling there you can really grown your bitcoin in a very very fast mood.
But most in gambling had no assurance that you can grow your coins instantly, because of the gamblers who played in gambling are depending to their luck or it depend on the games you are going to played. It is still much safe to invest your capital or to grow your coins in trading, and never invest in any cloud mining site it will just gonna waste your capital its dangerous and risky too.
After going through losses in the past from cloud mining sites I don't think now people would be interested in investing their money in those sites as they are well aware that they will not get anything in return and gambling is not for all to grow their bitcoins its only for those who have courage of taking higher risks and a person who wants to grow his bitcoins safely can always choose trading as that is a better option in compare to gambling.