I think the one question you need to answer for yourself is "what is my goal for investing, and is it long term or short term"?  Once you have established this then seek out where to invest.

Having a game plan and some knowledge is critical prior to jumping in too deep.

It's also a math game....

Put that $500 in Bitcoin today at $8200 and you'll need it to reach $16400 to double your money.

Put that $500 in an altcoin at $.04 and you'll only need it to reach $.08 to double your money.  Many altcoins swing daily like this, but profitability is there IF you have the right strategy.

I started with $800 a month ago.  It's been one hell of a wild roller coaster ride so far...