Surely isn't a sufficient amount if you are going to invest that with bankroll casino's. Though the price of bitcoin now is dropping.
Maybe investing that with bitcoin and just hold it again will be a good place to invest that $50.
Because after the dropping the price will possibly increase again and that $50 can be doubled easily by simply waiting.
To double your investment the bitcoin price would need to double as well. I dont think that is a short term gain, I mean bitcoin can see $2000+ but now right away. However the altcoin exchanges are more than just volatile its also open to speculation and manipulation.
If you get in the right time with some luck, you may get into an altcoin right before manipulation and gain 100% and even more thanks to people who does pump and dump.
You just need to be lucky and invest in the right thing at the right time. Of course you can do it right before dump and lose most of it as well, need to be careful. High risk high reward, low risk low reward. I think $50 is low enough of Money to invest on high risk stuff.