T-Mobile US Inc.'s stock was up 8.3% Wednesday after the cellphone carrier's fourth-quarter profit and revenue beat Wall Street estimates, boosted by strong net customer additions. The Bellevue, Wash.

AT&T (T) dropped its fourth-quarter earnings on Jan. 27, propelling its stock to new 52-week highs. Shares climbed 6.25% in ...

As Silicon Valley entrepreneur Peter Thiel once wrote, "Competition is for losers." When a firm enjoys little competition, it ...

Dallas, Texas-based AT&T Inc. (T) is one of the largest wireless service providers and leading communications service carriers in North America. With a market cap of $175.1 billion, AT&T operates ...