(CBS News) On Monday Fortune magazine released their Fortune 500 list, an annual survey of the largest companies in the U.S., ranked by revenues.
And while the group of front-runners is comprised of familiar faces, one company made a notable entry to the list less than a year after going public: Facebook.
Warren Buffet's Berkshire Hathaway moved up the list to this year's fifth spot.
Fortune's managing editor Leigh Gallagher told "CBS This Morning" the list generally reflects "a lot of activity" since 2012, namely "spinoffs and a lot of merger activity."
"Business is getting active again . . . they're starting to do things after being on the sidelines for the past couple years," Gallagher explained. "Now, of course the next question is when are they going to start to hire again."
The list also reflects some new moves for tech giants Apple and Facebook.
"Apple breaks into the top ten for the first time this year at number six," Gallagher said Monday. "The story with Apple has been its profits. If you were to rank the Fortune 500 by profits only [instead of revenues], they would be number two behind Exxon."
Facebook made the 2013 list for the first time in the company's brief history. The 482 ranking "makes Mark Zuckerberg the youngest person on the list," Gallagher said.
"This company rocketed onto this list . . . as fast as Google did," she said of the social network. "In the tech world, innovation happens a lot quicker. Years ago it would have taken decades."
To hear more from Gallagher click on the video above.
The 2013 Fortune 500 Top 10
4. Phillips 66
5. Berkshire Hathaway
7. General Motors
8. General Electric
9. Valero Energy