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.

Although the holiday season is well behind us and we're already halfway through January, Wall Street's not quite done reflecting on December's festivities. Investors were in a festive mood all over again Tuesday, as surprisingly robust December retail sales gave further indication that the U.S. economy's healing process is well under way. Excluding auto sales, December retail revenue rose 0.7%, meaningfully above the 0.4% growth that was expected. Sure, a 0.7% uptick is nothing earth-shattering, but considering the meager expectations it was enough to provoke a rally in the stock market today. The Dow Jones Industrial Average (DJINDICES:^DJI) surged 115 points, or 0.7%, to end at 16,373. 

Walt Disney (NYSE:DIS) stock ended as one of the Dow's top gainers, tacking on 1.6% Tuesday. If a full-fledged U.S. recovery is indeed in the works, Disney shouldn't be a bad name to hold, as Americans shell out their discretionary income on things like, oh, entertainment, for instance. Of course, the "proof is in the pudding," as they say, and as Disney shareholders are aware, this company makes nothing but high-proof pudding. Its animated holiday film Frozen stands out as a recent example of Disney's consistency, as the film took in more than $710 million worldwide since its November opening.

The largest franchisee of Disney's Dow peer McDonald's restaurants, Arcos Dorados Holdings (NYSE:ARCO), fell 2.8% today, as Bloomberg reported the price of a Big Mac Combo is set to slump in Venezuela. In 2012, more than 80% of Arcos Dorados sales came from a set of just five countries and territories: Argentina, Brazil, Mexico, Puerto Rico, and Venezuela. The company is in a privileged position, having the right to own, operate, and sell franchise rights to McDonald's restaurants in 20 Latin American countries and territories. The less stable nature of these economies is evidenced by the Big Mac Combo price reduction, as Venezuela struggles to combat steep inflation.

Finally, shares in the volatile Chinese e-retailer, aptly named E-Commerce China Dangdang (NYSE:DANG), rocketed 9.4% higher today. Massive swings like today's aren't unusual in Dangdang shares, which have a "beta" of nearly 5. Beta is an imperfect but sometimes useful measure of volatility, gauging how amplified or subdued a stock's swings are likely to be relative to the broader market. A high beta in theory means the stock will outperform in surging markets (and vice versa), but Dangdang investors beware: The small Chinese e-tailer hasn't posted an annual profit since 2010.