On August 4, 2007, The Wall Street Journal ran a cover story profiling Slim. The article said, "While the market value of his stake in publicly traded companies could decline at any time, at the moment he is probably wealthier than Bill Gates". On March 29, 2007, Slim surpassedWarren Buffett as the world's second richest person with an estimated net worth of US$53.1 billion compared to Buffett's US$52.4 billion. According to The Wall Street Journal, Slim credits part of his ability to discover investment opportunities early to the writings of his friend,futurist author Alvin Toffler.
On August 8, 2007, Fortune reported that Slim had overtaken Gates as the world's richest man. Slim's estimated fortune soared to US$59 billion, based on the value of his public holdings the end of July. Gates' net worth was estimated to be at least US$58 billion.
On March 5, 2008, Forbes ranked Slim as the world's second-richest person, behind Warren Buffett and ahead of Bill Gates. On March 11, 2009, Forbes ranked Slim as the world's third-richest person, behind Gates and Buffett and ahead of Lawrence Ellison.
On March 10, 2010, Forbes once again reported that Slim had overtaken Gates as the world's richest man, with a net worth of US$53.5 billion. Gates and Buffett now have a net worth of US$53 billion and US$47 billion respectively. He was the first Mexican to top the list. It was the first time in 16 years that the person on top of the list was not from the United States. It was also the first time the person at the top of the list was from an "emerging economy."