Despite Sprint's enormous $4.3 billion loss in 2012, shares of the nation's third-largest wireless carrier surged as executives tried to turn the business around, sparking a bidding war for its assets.
In October, Sprint Nextel agreed to sell a majority of the company to Japanese tech giant Softbank, a move most investors hailed as key for it to compete against larger rivals AT&T and Verizon. The $20 billion deal would also give Sprint the cash necessary to avoid bankruptcy if its ongoing network transformation plan doesn't go well.
The company has long struggled to recover from the 2005 merger with Nextel. It has been spending billions of dollars to build a next-generation data network to support the latest smartphones like the Apple iPhone 5.
The deal with Softbank is expected to close later this year, but it may not end up happening. In April, Dish Network stepped up with an offer of $25.5 billion for control of Sprint. Softbank executives remain confident their bid will prevail.
Wal-Mart retook the top spot, Berkshire Hathaway made the top five, and Apple grew enormously.