The article seems to indicate that those gains are all paper money due to the huge inflation in the stock market. On paper they look richer, but they can't do much with their "money" anyway. I think a more rational measure of inequality is through the possession of "important" assets like real estate, lands, power (political influence, ...). Of course the real problem comes when the lower and middle class sells their real wealth for stocks at the top, and the 1 percenters sell them their paper gains for "important" assets.