How a book that inspired Warren Buffett and a $14,000 side hustle helped billionaire Bill Ackman get started as an investor

Billionaire Bill Ackman has built a $35 billion hedge fund, led high-profile overhauls at companies like Chipotle, and boasts an eye-watering investment portfolio through his firm, ranging from Amazon to Microsoft. Now he’s revealing the two things that moved the needle in his career: a book that inspired Warren Buffett and a $14,000 side hustle.

“One early formative experience was at Harvard, where I took a job at Harvard Student Agencies selling advertising for the Let’s Go travel guides—a series of books where Harvard students wrote reviews of hotels around the world,” Ackman recently told editor-in-chief Alyson Shontell during Fortune podcast Titans and Disruptors of Industry. 

“It was a commission-based business, and I turned out to be a good salesman,” he continued. In fact, he was so good at the job that the student agency was afraid he would outearn his superiors. “I made $14,000, which felt like a huge amount of money.”