It's definitely possible to make a living out of bitcoin, but you will have to invest allot of money to make allot of money back.
If you're not investing as much don't expect to make lots of money fast. If you start with a low budget it will take some time before you will earn lots of money.
Agreed, you would need some serious investment in bitcoin to be able to make a stable monthly profit, trading rarely can provide a stable profit so starting and running your own bitcoin project is the way IMO.
indeed the result of the trade is not stable. but trade can make you get high profits in a short time. I saw some friends who always get a big advantage in trade. even I ever saw him get 5 BTC in 2 days.