The Dow Jones Industrial Average (DJINDICES:^DJI) is down 67 points, or 0.5%, as of 2 p.m. EST. Among the heavier downdrafts, Verizon Communications (NYSE:VZ) is down 2.2% and AT&T (NYSE:T) lost 1.5%. What's going on with America's largest telecoms today?

At the heart of the matter, AT&T just released smartphone sales numbers for the holiday quarter. The announcement was heavy on cheerful spin and short on good news: Unit sales increased a paltry 6% year over year, landing just north of 10 million handsets.

Ma Bell rightly calls it a "record" quarter but never acknowledges that the days of double-digit hypergrowth are over. It looks like the low-hanging fruit has been harvested, which is bad news for margins and sales growth across the industry. The news spilled over into an industrywide rout that took all the momentum out of a recent rally:

T data by YCharts.

AT&T also noted record sales of Apple (NASDAQ:AAPL) iPhones and Android handsets but didn't provide hard sales numbers for either category. Apple traded sideways today, easily beating the Dow. And that doesn't make much sense in the light of AT&T's disclosure.

The most rosy-cheeked interpretation I can come up with would be that minor smartphone players Research In Motion (NYSE:BB) and Nokia (NYSE:NOK) crashed so hard that Apple and the Android army actually delivered halfway decent numbers. Even then, that doesn't help the most hard-suffering half of the handset industry. It might be time to look for the next, next big thing in mobile computing.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.