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 thesis.

What: Shares of Under Armour (NYSE:UAA) were looking tougher than ever today, jumping as much as 25% to a new record on a blowout fourth-quarter earnings report.

So what: The report from the sports-apparel specialist comes at a time when many retailers, including rival lululemon athletica, have turned in disappointing holiday earnings. Under Armour, however, bucked that trend, posting a profit of $0.59 a share, better than expectations of $0.53. Its top-line performance was even stronger, as revenues jumped 35%, to $682.8 million, topping the consensus at $619.9 million. CEO Kevin Plank called 2013 a "banner year," noting that the company completed its first acquisition, purchasing MapMyFitness, and opened the first of its two UA Brand House retail stores.

Now what: Under Armour also raised its guidance for 2014, saying it expects sales growth of 22%-23%, or total revenue of $2.84-$2.87 billion, above the consensus at $2.77 billion. Plank explained, "We have tremendous momentum across our business and we will leverage this strength to fuel our global growth ambitions in 2014." In addition to the major steps taken above, the company recently signed partnerships with Notre Dame and Navy, two high-profile programs that should further spread its brand appeal. The stock is certainly pricey, but with growth opportunities aplenty, Under Armour seems like it may just be on the cusp of an athletic-apparel empire.