359. Eric Lefkofsky
$2.2 billion Self-made Score: * Source: groupon age: 48 residence: chicago J.d., u. of michigan ’93
lefkofksy made his initial fortune from the daily-deals site groupon, which he cofounded in 2008, but after his wife was recently diagnosed with breast cancer, he set his sights on health care. he founded tempus, a startup focused on using data to treat cancer, in 2015. partners include the mayo clinic and cleveland clinic. tempus announced a $70 million funding round in september, pegging the company’s valuation at $700 million. after a girlfriend dumped him his freshman year, lefkofsky started his first of at least 9 businesses: selling carpets.