Winfrey, who debuted on the list in June at No. 494 and is now at No. 489, is the first black female entrepreneur to make it onto the list. She's gaining on famous businessmen like John Paul DeJoria, who sits at No. 483 with a net worth of $4.04 billion, and investor Mark Cuban, who sits at No. 476 with a net worth of $4.08 billion. The Bloomberg Billionaires Index updates members' net worth, based on changes in markets, the economy and Bloomberg reporting, after the close of trading in New York each day.
Winfrey, 64, is having a terrific year.
Her latest boost in wealth comes thanks primarily to her investment in Weight Watchers. In 2015, Winfrey put $43 million in the company and got a 10 percent stake. Though her stake is now down to 8 percent, the investment continues to benefit both. It was the company's recent stock rally on June 12, which sent share prices to record highs, that tipped Winfrey's wealth over $4 billion.