1. Warren Buffett
> Company: Berkshire Hathaway Inc.
> Value of shares: $56.5 billion
> CEO since: 1970

Warren Buffett has been the CEO of Berkshire Hathaway Inc. (NYSE: BRK-A) for more than 40 years and has been the controlling shareholder of the company since 1965. In 2010, Buffett told CNBC that he began acquiring shares in Berkshire Hathaway in 1962, when the company was a failing textile maker. He only decided to buy up the company after feeling he had been ripped off by its former management when he offered to sell back his stock to the company. Today, less than 50 years later, Berkshire is one of the world’s largest companies, and Buffett is possibly the most celebrated investor of all time.

Also Read: The Countries with the Most Multimillionaires

2. Larry Ellison
> Company: Oracle Corp.
> Value of shares: $35.8 billion
> CEO since: 1977

Oracle Corp. (NYSE: ORCL) was founded in 1977, when three engineers formed Software Development Laboratories to build a CIA database program code-named “Oracle.” More than 35 years later, the company continues to build and sell databases, as well as a range of IT services and products, software and hardware. One of the three original founding engineers, Larry Ellison, has served as CEO from the outset. During that time, he has amassed a massive fortune, with nearly $36 billion in company stock. Outside of his role at Oracle, Ellison recently has generated controversy for his role in attempting to transform the America’s Cup, a long-running and prestigious sailboat race, into a made-for-TV event. Critics have accused Ellison of allowing participation in the event to become too dangerous after a New Zealand team sailor died in practice.

3. Jeff Bezos
> Company: Amazon.com Inc.
> Value of shares: $25.4 billion
> CEO since: 1996

Jeff Bezos founded Amazon.com Inc. (NASDAQ: AMZN) in 1994. By July 1995, the company began selling products online. Less than two years later, in May 1997, the company completed an initial public offering (IPO) at just $18 a share (or, splits adjusted, just $1.50 a share, according to the company). Currently, shares trade at close to $300. In 1999, Time magazine named Bezos Man of the Year, and he was hailed as having changed retail. Recently, Bezos has been in the news for his purchase of the Washington Post for $250 million in cash from the Washington Post Co.

4. Sheldon Adelson
> Company: Las Vegas Sands Corp.
> Value of shares: $24.9 billion
> CEO since: 1988

Sheldon Adelson is the founder, and current chairman and CEO, of hotel and casino company Las Vegas Sands Corp. (NYSE: LVS). According to the company, Adelson first found success as a trade show owner — he started the computer trade show COMDEX in 1979 and later sold it for $800 million in 1995. Adelson bought his first hotel, the Sands Hotel, in 1989 and began building his resort empire in 1996, when he imploded the Sands Hotel to build The Venetian. Adelson was key in helping to bring convention travelers to Las Vegas, the company notes, and his relatively early expansion into Asia was hailed as highly successful. In addition to his work with Las Vegas Sands, Adelson is also a prominent political donor and supporter of the Birthright Israel Foundation.

5. Larry Page
> Company: Google Inc.
> Value of shares: $21.5 billion
> CEO since: 2011

Larry Page is the co-founder of search engine giant Google Inc. (NASDAQ: GOOG), along with Sergey Brin. The two started Google in 1996 as a research project while they were Ph.D. candidates at Stanford University. Initially, the search engine was called BackRub and ran on the university’s server. By 1998, Google had incorporated and was named by PC Magazine as one of the year’s top 100 websites. PageRank, the key component of the company’s search algorithm, which assigns a level of importance for any given webpage, is named after Larry Page. In 2004, Google went public, turning more than 1,000 employees into millionaires while making Page and Brin billionaires. In 2006, Google acquired YouTube, giving the company ownership of two of the most widely trafficked websites in the world. In early 2011, Page was named CEO of Google, replacing Eric Schmidt, whom Page and Brin had hired in 2001 to help manage and direct the company.