If you can invest big amount to buy some btc then i guess you can earn huge profiit in near future! because btc price is upper!
Gambling is one of thr thing i know that you can able to get 1 bitcoin or much higher income in a month. But it is too much risky than trading, gambling is for people who have lot of capital but if your capital is few i thing you must go on trading without requiring minimum investment.
yes gambling is really the shortest way of earning bitcoin and you can make more than on bitcoin in a moth, but in fact gambling is one of the most risky way of making money, there are more chances to lose your own money,