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 specialist Millennial Media, (UNKNOWN:MM.DL) surged 13% today after its preliminary Q4 results impressed Wall Street.

So what: The stock has plunged over the past year on weak revenue and widening losses, but today's better-than-expected report suggests that things are starting to turn. Additionally, Millenial announced that its co-founder and CEO Paul Palmieri was resigning and would be replaced by Yahoo! executive Michael Barrett effective immediately, triggering optimism that a fresh perspective will keep the positive momentum going.

Now what: Management now expects Q4 adjusted EBITDA of $5 million-$6 million on revenue of $106 million-$109 million. "The integration plan is ahead of schedule, enabling us to complement our historical strength among brand advertisers with market leading solutions for our performance clients through our demand-side programmatic buying capabilities and our premium exchange (MMX)," said CFO Michael Avon. "Millennial Media enters 2014 with a much stronger and more comprehensive suite of capabilities than at this time last year positioning us well to capitalize on these assets in the year ahead." So while Millenial's competitive position is still too frail for conservative investors to bet on, less risk-averse traders might want to look into the stock as potentially juicy turnaround opportunity.