It's more like they have tons of more money and larger numbers in their portfolio. it's however not a significant increase in actual wealth, since the money they have is increasingly wort less and the worth of their assets are increasingly more and more speculative in nature. The pockets of billionaires is where all the printed money eventually ends up and society is no richer for it. The money contributes to inflation, but it really doesn't get invested or anything.

Everyone's wealth doubled.