The Dow Jones Industrial Average (^DJI 0.62%) was falling in late-morning trading on Wednesday, shedding 71 points as of 11:30 a.m. EST. Telecom giant AT&T (T -0.27%) led the index lower, down more than 1.6%. A few tech stocks, however, were outperforming the market -- most notably, both Yelp (YELP 0.50%) and Micron Technology (MU 2.55%) posted big gains early on Wednesday.

ADP data suggests stronger labor market
Data from private payroll company ADP suggested that the U.S. labor market is improving. According to ADP, private employers added some 238,000 jobs last month, more than the 200,000 economists had anticipated. While that's a positive sign, the ADP report generally isn't given as much weight as the official, nonfarm payroll number from the Bureau of Labor Statistics. Thus, despite the positive data, investors were selling stocks, leading to a move lower in the Dow Jones.

AT&T drops on T-Mobile leak
Dow component AT&T was a notable loser, possibly due to a leaked ad from rival T-Mobile. The smaller wireless carrier has been coming after AT&T aggressively in recent months, rolling out a series of "un-carrier" iniatitves aimed at stealing AT&T's subscribers.

The leaked ad highlights a forthcoming deal that would see T-Mobile paying off families' early termination fees if they make the switch. If that turns out to be the case, AT&T could lose more subscribers to T-Mobile in the coming months, weighing on the wireless provider's performance.

JPMorgan Chase upgrades Yelp
Meanwhile, Yelp shares had surged 8.5% in morning trading. The move was likely prompted by a positive note from JPMorgan Chase. While the bank has long been bullish on the stock, maintaining an overweight rating, it became even more bullish on Wednesday, raising the price target from $75 to $89.

JPMorgan based its upgrade on what it perceives to be strong ad coverage in most of the U.S., as well as strong adoption of Yelp Deals by advertisers in the recent quarter.

Micron reports solid quarter
Micron's rally was even more impressive than Yelp's, with shares posting a double-digit percentage gain early on Wednesday. The rally follows a strong quarterly report in which Micron's earnings exceeded analysts' expectations. For the quarter, Micron earned $0.77 on revenue of $4.04 billion. Analysts had only expected earnings of about $0.43 on revenue of $3.72 billion.

Micron is primarily a maker of flash memory products, with a portfolio of DRAM and NAND chips. The continued growth of mobile devices seems to be benefiting Micron.