10. ALICE SCHWARTZ
$2.9 billion SOURCE: Biotech AGE: 95 • RESIDENCE: El Cerrito, CA SELF-MADE SCORE: With $720 in savings, Schwartz and her husband, David (d. 2012), launched BioRad Laboratories in 1952. In the years since, Bio-Rad has flourished by selling chemicals and components that are instrumental to lab research. At age 95, Schwartz still sits on Bio-Rad’s board and has an 11% stake in the $2.5 billion (2020 sales) company run by her son Norman Schwartz.