In-N-Out Burger president and owner Lynsi Snyder became the world's youngest billionaire — according to the Bloomberg Billionaires Index — when Forbes changed Theranos founder and CEO Elizabeth Holmes' estimated net worth from $4.5 billion to zero! (That's a whole other story.)

Snyder, the sole owner of In-N-Out Burger — she received full control on her 35th birthday — is currently worth $1.21 billion, according to Forbes.

Snyder, who largely stays out of the spotlight, has already been married four times and has four kids. In 2014, she told Orange Coast magazine that she's twice been the target of kidnappers.