How to capitalise on deepening wealth inequality?

So I notice that regardless of the economic environment, asset prices go up.

GDP goes up, but GDP per capita goes down, this ties in with median earnings after inflation going down.

What is the best way to "bet" on ever increasing wealth inequality and to bet on 99.99% of all assets eventually being owned by the wealthy?

At the moment I invest in stocks but wonder if there is another way.