Peter Cancro was just 17 when he pulled off a deal that would shape his destiny. In 1975, with a $125,000 loan from his football coach, the high school senior bought Mike's Subs, a Point Pleasant, New Jersey sandwich shop where he had worked since he was 14. At the time, Cancro wasn't even old enough to legally operate the deli slicer. Fast forward nearly 50 years and that teenage gamble has turned Cancro into a billionaire.

Jersey Mike's Subs, as the shop was rebranded, has grown into a global franchise powerhouse. On Tuesday, private equity titan Blackstone announced it had agreed to acquire a majority stake in the company, valuing it at roughly $8 billion including debt. The deal bumps Cancro's net worth to an estimated $7.5 billion, according to Bloomberg.