Kim Kardashian’s Hair Fixer Created a $10 Billion Buyout Bonanza

A hair-care startup that was helped out of obscurity by an endorsement from Kim Kardashian is on track to earn its private equity owner one of the biggest and fastest payouts in the history of the industry.

Advent International led the purchase of Olaplex Holdings Inc. in January 2020 and in little more than two years, the firm has pulled out nearly triple its initial investment and is sitting on a stake worth around $9 billion -- if it can hold on to those gains.

Despite a 38% plunge in Olaplex’s stock this year, the return is still more than ...