Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of mobile advertising service specialist Millennial Media, Inc. (UNKNOWN:MM.DL) sank 15% today after its quarterly results and outlook disappointed Wall Street.

So what: The stock has plunged in 2013 on rapidly slowing growth, and today's Q3 results -- adjusted bottom line of breakeven on a revenue increase of 18% -- coupled with downbeat guidance only reinforce that disappointing trend. In fact, year-over-year gross margins slipped 130 basis points, while operating expenses spiked 27%, suggesting that the company's competitive position continues to weaken.

Now what: Management now expects Q4 adjusted EBITDA of breakeven to $2 million on revenue of $95 million to $100 million. "Through our acquisition of Jumptap, the global launch of MMX, our mobile ad exchange, and the introduction of our Omni Measurement suite, we are uniquely positioned to be the partner of choice to the world's largest advertisers and agencies," CEO Paul Palmieri reassured investors. "Our integration is going well and we are very enthusiastic about bringing our combined capabilities to the global mobile advertising market." More important, with the stock now off about 60% from its 52-week lows, Mr. Market might be offering contrarians a juicy opportunity to benefit from that improvement.