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

What an up-and-down two weeks it's been on the markets! After a couple hundred-point plunges over that time, the Dow Jones Industrial Average (^DJI 0.62%) is bouncing back today with a stellar performance. The Dow's picked up more than 90 points as of 2:30 p.m. EST, buoyed by the rise of the large majority of its blue-chip stocks on the day. No stock is having a better day on the index than Nike (NKE 0.04%), as the soaring athletic apparel stock's jumped 2.7% today. Meanwhile, earnings season goes on around the Dow, with credit card giant Visa's (V 1.22%) stock picking up 1.1% in gains after a strong quarterly performance. Let's catch up on the biggest news around the markets.

Consumers keep the recovery on track
The U.S. economy kicked the market day off with some strong news this morning, as reports filtered in that American GDP posted 3.2% annualized growth in the fourth quarter, according to the Department of Commerce. Full-year U.S. GDP growth fell to 1.9% from 2012's 2.8% jump, but the latter half of 2013 showed enough promise to bode well for 2014 if economic momentum continues. In particular, consumer spending jumped 3.3% for the fourth quarter, a huge plus for the economy as consumption makes up the majority of American GDP.

Higher consumer spending is good for credit card giants such as Visa, and this stock's blown up today in the wake of a well-received fiscal first-quarter performance. Visa's net profit jumped nearly 9% for the quarter and operating revenue climbed 11% as the company saw double-digit overall payments volume growth. That was enough to beat analyst projections on both the top and bottom lines, giving investors an optimistic look forward for a stock that's gained more than 41% over the past year. Visa is projecting double-digit growth in both earnings and revenue for 2014, and if consumer spending continues to pick up steam in the United States, investors should see welcome returns.

Nike's moving in a big way today, and this is one stock that hasn't had any problems over the past year: In that time, Nike's stock has gained more than 37% and would have picked up more if not for a downbeat past three months. While Nike's seen emerging-market growth sag lately -- revenue growth in those regions gained only 3% even before currency issues are accounted for in the company's most recent quarter -- the company is still acing every test in its largest markets of Europe and North America. The former in particular has been a huge driver of Nike's growth lately, as sales in western Europe over the past six months ramped up by 14%. If Nike can keep up its rebound in China while continuing to see steady growth in North America and Europe, this stock will be poised to take another leap in 2014.

However, Nike's got tough competition. One of the company's leading rivals is taking the markets by storm today, with Under Armour (UAA -1.72%) stock erupting for a 21% gain. Under Armour posted a 28% gain in net profit in its fourth quarter as announced today, and more importantly, revenue roared higher by 35%. That's the 15th straight quarter of revenue growth of more than 20%, according to CEO Kevin Plank, and Under Armour is picking up market share in the hotly contested sportswear space. For Nike investors, there's no hotter rival out there than Under Armour right now, and today's big surge should only fuel the budding rivalry between these two top sports stocks.