We have not really discussed alternative asset classes yet.
I did mention that investors with specialized knowledge may be able to excel in market segments relating to their expertise. Conversely, investors with little to no knowledge, will have difficulty investing in these segments.
Some examples are fine art, stamps, coins, and gems.
Fox Business has an interesting article on buying diamonds .
It is an excellent example of the nuances involved in the retail diamond market.
Unless you possess specialized skills in a market niche , be very leery about investing directly* in that market. You will be competing against experts and, unless you are one too, you will be at a disadvantage.
Being a novice in a complex marketplace is usually a fool’s game.
*Novices can participate in specialized niche markets indirectly; through mutual funds or managed accounts. In these cases, presumably an expert is trading on your behalf. Of course, you will pay for that expertise and it can be costly.