There’s a certain confidence that comes with being a billionaire.

Spanx founder Sara Blakely has it. On this November morning she’s at her Atlanta office, lounging on a red, white, and black paint-splatter-patterned couch and dressed, appropriately enough, in Spanx’s new loungewear. “Mick Jagger just asked me to send him these,” she says by way of introduction, gesturing at the cozy-looking set.

In just two days, after 21 years of owning and running Spanx, Blakely would close on a deal that sold a majority stake in her company to Blackstone, a transaction that values the shapewear maker at $1.2 billion. It launched Blakely, already wealthy from her years of operating the booming business, into a new realm: “The difference now is, I’ve monetized the value,” she says.

The past year has been a turning point for female founders, with not just Blakely, but also Whitney Wolfe Herd of dating app company Bumble, and Anne Wojcicki of genetics startup 23andMe crossing a rare threshold: female founders and CEOs who have sold or taken their company public—and achieved billionaire status in the process.

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