We should significantly increase capital gains taxes by taxing it at the same rate as ordinary income.
If an investor makes money one year then loses it later, we should give them their taxes back.
I wonder how progression would interact with the giving back. I.e. if you had gains while being a high-maginal-rate taxpayer and then losses at a lower rate or vice versa.
Nit: IMHO consumption distribution would be much more relevant than wealth. You can imagine a society where everyone gets and consumes enough materially (for some definition of “enough”) – which counts as 0 wealth, but some of its members also own stocks…
(Lacking decent consumption data, income would probably be a much closer approximation than wealth).