219. Sid Bass
$3.4 billion self-made score: $ source: oil, investments age: 75 residence: fort Worth, tex. m.b.a., stanford ’68 In late 2016, Bass negotiated with Exxonmobil’s then-ceo, Rex Tillerson, to sell his family’s oilfields in New Mexico for $5.6 billion in stock (with up to $1 billion more in contingent cash payments). Other benefactors from the sale, which was announced in January, include his 3 brothers, Robert (No. 122), Lee (No. 315) and Edward (No. 324). Sid has been an astute investor since the late 1960s; he partnered for many years with star investor (and former Forbes 400 member) Richard Rainwater (d. 2015). The family fortune stems from successful bets on Texas oil in the 1930s by the siblings’ greatuncle Sid Richardson.