I would invest in something like trading or gambling just for the fun its not that its necessarily to invest it into something good right ?
It was not asked if it should be something right, but it was obvious that the guy needs an idea on where to invest it and that means the OP needs some idea on how to earn more from his regular $40 earning each day. With that, I am sure that OP needs something that earns, so your first suggestion is good but the second which is gambling, that's off!