You can look into trading with your bitcoins, trading your bitcoins into other altcoins would be a good choice if you know the market trend well. Investing your bitcoins into some of the casino bankroll is another good way to earn some profits, because there is a house edge that are in casino advantage so there is a higher chance for players to lose against the casino, but there is still a chance for players to win huge amount of money from casino, and you might lose some bitcoins if that happens.

Never invest into ponzi scheme that promise to give you huge profits in a very short time, most likely the scammers would just take your bitcoins and run away.