Facebook's Sheryl Sandberg becomes one of world's youngest billionaires
She owns around 12.3 million shares in the company.
In addition, she has amassed over $300m by selling Facebook shares since the firm's flotation in 2012.
“She was brought in to figure out how to make money,” David Kirkpatrick, author of The Facebook Effect, a history of the company, said in a telephone interview with Bloomberg.
“It’s proving to be one of the greatest stories in business history.”
She is attending the World Economic Forum’s annual meeting this week in Davos, Switzerland.