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 Roundy's Inc (NYSE: RNDY) were put on special today, falling as much as 26% after an underwhelming first-quarter earnings report.

So what: The Midwestern supermarket chain said sales ticked up 1.9% to $1 billion, while adjusted profits fell from $0.19 per share a year ago to a penny. Its revenue result matched estimates, but the company missed on the bottom line as analysts had expected a $0.03 per-share profit. CEO Robert Mariano noted continued softness in the company's core markets as sales were affected by competitive pressure, poor weather, and weak economic growth. Same-store sales fell 5.2% in the quarter, a reflection of organic weakness in the company.

Now what: With Roundy's legacy stores suffering, the future of the company seems to be tied to Mariano's Fresh Market, its "growth banner" which is in the process of filling in former Dominick's locations in Chicago. Roundy's has opened 7 Mariano's locations in 2014, bringing the grand total to 21. Separately, Roundy's announced the sale of 18 Rainbow stores for $65 million, compliant with its plans to exit the Minneapolis/St. Paul market. With those two moves, Roundy's is clearly a company in transition, and the aggressive Mariano's expansion could make it an appealing buy at today's price. The supermarket chain isn't out of the woods yet, though, as the company still expects declining same-store sales for the remainder of the year -- but this is a stock that's worth keeping your eye on. You can add Roundy's to your Watchlist by clicking right here.