50 is really not bad.. that's $600 a year
My suggestion:
Every month convert your $50 to ETH/BTC, at the same time search for popular ICO's or what you think might have a future
If you one of your ICO prediction is correct, you'll multiply your investment and will be able to exchange it for more ETH/BTC or whatever you want
but in general, stick with ICO's - since as you said 50 isn't a lot and ICO's offer the best return on investment
Good luck
While an ICO might have the best
potential return, I believe maybe only 1 or 2 out of the hundreds that are being offered might succeed. Most are outright scams. Investing in an ICO takes a lot of research and vetting if you don't want to lose your money.