The only thing that can help you to get a profit for $5000 in 3-15 days with investing $15 is MAGIC. But you never know if that thing will happen to you or not. That will not be possible to invest $50 and gain $5000 in a short time because the investment itself needs some time before you can make a profit. But the fact that it will be possible for you to lose your money if you don't invest in the right investment. How if you buy bitcoin as the investment and hold for a long time, maybe for more than 5 years. I think that will help you make a profit, but I don't know how much profit you will make.