What 10 CEO titans studied in college before making it big

It can be difficult to imagine, but once upon a time, the CEOs of America's biggest companies were just college kids too — albeit incredibly intelligent ones.

They also had to balance studying for exams, hanging out with friends and figuring out what to do with the rest of their lives.

So what did they study that eventually led them to the helm of the country's mega companies?

It turns out there is no clear-cut path to landing in the CEO suite of America's 10 biggest companies by market cap. By and large though, these chief executives majored in the STEM (or science, technology, engineering and math) fields before climbing the corporate ladder. Some have advanced degrees — but far from all of them. One was even a college dropout.

Click ahead to find out what corporate heavyweights like Berkshire Hathaway CEO Warren Buffett and Amazon CEO Jeff Bezos studied in school.

—By CNBC's Katie Little
Published 25 March 2016

More than three decades ago, Stumpf joined a predecessor of Wells Fargo. Before that, he earned a bachelor's degree in finance from St. Cloud State University in his native Minnesota. He later went on to earn an MBA with an emphasis in finance from the University of Minnesota.

Just eight years after graduating from Princeton University, Bezos founded Amazon.com, which would grow into the e-commerce behemoth it is today. While at Princeton, he majored in electrical engineering and computer science, performing well enough to graduate summa cum laude and Phi Beta Kappa.

Continuing the STEM trend, Immelt earned his bachelor's in applied mathematics from Dartmouth College and an MBA from Harvard University four years later. A veteran of GE, Immelt has been with the company for more than three decades.

J&J's Chief Executive Gorsky completed a Bachelor of Science degree at U.S. Military Academy at West Point, N.Y., before rising to the rank of captain in the Army. Later, he earned an MBA degree from University of Pennsylvania's The Wharton School.

Zuckerberg is the only member of the list who never graduated from college. He attended Harvard University, where he studied computer science but dropped out to focus on growing Facebook full time.

Like many of the executives on this list, Tillerson has been with his company for many years — to the tune of more than four decades. Before beginning at Exxon, Tillerson earned a Bachelor of Science degree in civil engineering at the University of Texas at Austin.

Long before he earned the nickname the "Oracle of Omaha," Berkshire's Warren Buffett was just another college student with an interest in finance. He graduated from the University of Nebraska with a Bachelor of Science in business administration before earning a master's in economics from Columbia University, where he enrolled after learning Benjamin Graham taught there. Graham, an economist and investor, is often credited with being the father of value investing.

Microsoft head honcho Nadella has not one but three degrees under his belt. First, he majored in electric engineering at Mangalore University in his native India. After his bachelor's, he earned a master's degree in computer science from the University of Wisconsin, Milwaukee, and a master's degree in business administration from the University of Chicago.

Alphabet's Page graduated with a Master of Science degree in computer science from Stanford University and a Bachelor of Science degree in engineering, with a concentration in computer engineering, from the University of Michigan.

Before taking the reins from Apple co-founder Steve Jobs, Tim Cook earned a Bachelor of Science degree in industrial engineering from Auburn University and an MBA from Duke University.