Tied for second place last year were Columbia University, Stanford University, Texas Tech University and University of North Carolina. Each school produced three CEOs who took their companies public.
The seven newly publicly traded companies led by Harvard alumni range from online bank Ally Financial to pharmaceutical company Kite Pharma. The group notched an average gain of 74 percent from the date of their market debut to the end of the year. By comparison, the FTSE Renaissance US IPO index, which tracks the performance of U.S. initial public offerings, gained 9.6 percent last year.
The average gain of the companies led by Harvard-schooled CEOs was also better than that of other schools. The IPOs led by former University of North Carolina students rose an average of 39 percent. Stanford graduates posted an average gain of 37 percent. Texas Tech University graduates saw an average increase of nearly 7 percent, while IPOs led by Columbia alumni had an average loss of almost 3 percent.
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The Harvard executives are following one of the school's most famous students. Mark Zuckerberg, founder and CEO of Facebook, studied computer science at the school from September 2002 to May 2004 before leaving to focus on the social networking company. Facebook raised about $16 billion in its market debut in 2012.
Among the Harvard graduates who oversaw IPOs in 2014, two earned undergraduate degrees, one completed a residency at Harvard Medical School, while four earned graduate degrees, including two who studied at Harvard Business School.
Thomas Eisenmann, a professor at the business school, says that the program has been placing an emphasis on entrepreneurship for at least a decade. "It's a very strong focus for us," he said, noting that almost half of the school's alumni have started at least one company.
Kent Bennett, a partner at venture capital firm Bessemer Venture Partners, started at Harvard Business School in 2006 and says the school had not yet launched a lot of the formal entrepreneurship programs that now exist.
Still, he said, a lot of students wanted to start their own companies, and stories about others who attended Harvard and made names for themselves were motivating.
"It really helps when they're exposed to great role models," he said. "Maybe it's just the vision of Bill Gates or Mark Zuckerberg late at night ...That inspired them to think (they) could start a business."
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Microsoft founder Bill Gates, like Zuckerberg, attended the school, but did not graduate.
Last year's U.S. IPO market was strong. Demand for stocks remained high as the economy continued its recovery, corporate profits kept growing, and volatility in financial markets remained low by historical standards. A total of 293 companies raised $96 billion from initial stock sales, according to data provider Dealogic. That was the most cash raised from IPOs since 2000.