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 rent-to-own retailer Rent-A-Center (NASDAQ:RCII) plummeted 19% today after its quarterly results disappointed Wall Street.

So what: The stock has plunged over the past six months on signs of rapidly slowing growth, and today's fourth-quarter results -- in which income plunged 72% on a revenue increase of just 2% -- only reinforce that negative trend. In fact, same-store sales during the quarter fell 1.1% over the year-ago period, suggesting that Rent-A-Center's competitive position continues to weaken as well. 

Now what: Management now expects 2014 EBITDA of $325 million to $345 million on revenue growth of 4.5% to 7.5%. "We continue to face meaningful headwinds in our domestic U.S. rent-to-own business, including a customer under severe economic pressure and an intensified promotional environment," cautioned Chairman and CEO Mark Speese in a prepared statement. So while contrarians might be attracted to Rent-A-Center's beaten-down stock, there's likely plenty of room to fall given the revenue, cost, and competitive challenges that management continues to face.