Its never easy to multiply your coins in a quick way, either in trading or in gambling as both are the risky ways if you don't know how to handle them smartly, safest way is to simply hold them and wait for the price rise.
Just holding them you'll never make more Bitcoins, but I agree that if you are not an expert in trading you will almost definitely lose your money with it. Gambling is the fastest way to lose you coins though, there is no competition. )