There isn't such a thing as risk free profits with Bitcoin. If that was the case, every person buying himself into Bitcoin would be in the green already. In most cases people can't handle this market mentally, especially not when they invest with money that isn't meant to be invested, and that's exactly where the main risk lies. Everything is all right when the market is going up nicely, but things get a whole lot more serious for people when the market is tanking, and thus them seeing their initial investment lose value quickly. Another aspect that plays a role is people cashing out profits, where they then buy back their coins at much higher levels. The more often you do that, the lower your coin coint becomes -- it's called capital destruction.