T-Mobile (NASDAQ:TMUS) has stalled out over the past 14 months. A huge bull run in TMUS stock that lasted through last summer has officially ended, and I’m not terribly surprised.

That’s not a knock on T-Mobile. The company’s performance continues to be solid, and it has been the best name in the wireless space. But that’s not the issue. As I wrote last year, T-Mobile’s problem is that it’s the best stock in an unattractive industry. Competition for U.S. wireless customers remains intense, and wireless companies’ lack of pricing power hurts their margins.

The result is what I’ve called in the past a “circular firing squad,” and the pressure on the industry is reflected in the sector’s stocks. TMUS stock is up only several percentage points over the past year, and that’s with a 7.7% gain on Monday. Verizon Communications (NYSE:VZ) has gained less than 10% over the last twelve months, while both AT&T (NYSE:T) and Sprint (NYSE:S) have fallen over the past year.

This is still not a particularly attractive industry. And that’s why T-Mobile needs the Sprint merger to happen, and it explains why TMUS stock rose so sharply on Monday.