in 1990, kaiser bought bank of oklahoma out of federal deposit insurance corporation receivership. despite bok's depressed state, it was rich enough to land kaiser on the forbes 400 at one stroke. he has since expanded bok from a 20-branch company located solely in oklahoma into a $23.9 billion bank with operations in nine states. he owns 61.5 percent of bok. as of 2007, kaiser's ownership interests in bok were worth $2.3 billion. in 2008, with an estimated net worth of around $12 billion, he was ranked by "forbes" as the 20-richest person in america and the richest person in oklahoma. in march 2009, in the face of the general world economic downturn, "forbes" reported that kaiser's net worth had dropped to $9 billion, ranking him in a tie for 43rd-richest person in the world. it has since risen to $9.8 billion as the markets recovered. as of 2019, george's net worth was estimated at $7.6 billion.