Among living titans of industry, only George Soros springs to mind as a possible rival.
Maybe they can share the same oven in Hell for all eternity.
[Barring the miracle of Salvation.]
With respect to Buffet and Soros, there is an historical template being replicated. They are Twenty-First Century counterparts to Cecil Rhodes and J.P. Morgan. Neither of them really owns their wealth, they merely manage it. Unfortunately, there seem to be few left around here who will understand the reference... /grin