Do you?

His father, Tivadar Soros, wrote an autobiographical account in Esperanto in the 1960s, Masquerade: Dancing round Death in Nazi-occupied Hungary about how he secured false Christian identities for himself, his wife and their two children, Paul and George to escape the holocaust. The book has been translated from Esperanto into English by Humphrey Tonkin, so that both Esperanto and English versions are available from UEA. The book ends with the defeat of the Nazi occupiers of Hungary by the Red Army, which ushered Communist rule into Hungary as a satellite of the Soviet Union. Tivadar Soros escaped from Hungary in 1956 during the short-lived rebellion against Soviet domination and reached the United States, where his son George became an internationally famous financier, philanthropist and political activist.

But a frequent question is whether George the son knows or knew Esperanto.

http://en.wikipedia.org/wiki/George_soros says that George learned Esperanto from childhood, but does not clarify if he kept up with it or forgot about it.
http://eo.wikipedia.org/wiki/George_Soros says that it's only known that George learned Esperanto in his youth, not that he is still an Esperantist.

It seems likely that George does not currently use Esperanto; at least I've seen no evidence of it.

The anthology "Trezoro: Esperanta novel-arto" has a selection from the novel "Modernaj Robinzonoj" by the father Teodoro Schwartz-Soros.
http://eo.wikipedia.org/wiki/Teodoro_%C5%9Cvarc