Estimates will vary, but most experts agree that investors should aim for a small percentage of their portfolio. Ideally, this could be 10% or less based on your investment timeline and risk tolerance.  Be realistic and study the key information of any alternative investment you’re considering. Some of these have more of a proven track record than others. You don’t want to get caught up in the hype of something you don’t quite understand. That’s an easy way to lose a lot of money.