Depends how aggressive you want to be with it but I would spilt it up into 5 bits then pick 2 coins from the top 25, another 2 from the top 25-200, and then one coin outside that for a pure gamble. That way you diversify and at the same time are in some solid coins too.
i dont think $50 fits on what you are trying to advice here mate,imagine how much each coin would be if this all coins will indeed..better put the whole funds in single coin but make sure that you had make a deep research about the said coin,and made checked about the team and project.though for me this capital is little short for crypto investnt