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.

The Dow Jones Industrial Average (^DJI 0.69%) fell for a fifth straight day on Monday, as jitters over the stability of emerging markets continued to worry Wall Street. Blue chips have now lost nearly 4% in the past week alone, a sudden sell-off sparked by unexpectedly weak data from China's robust manufacturing sector. Soft December new home sales in the U.S. also failed to reassure the stock market today, although I think taking a broader view of real estate is more helpful for investors. Zooming out a bit, we see that the 428,000 new homes sold in 2013 is actually the most since 2008, which is nothing to scoff over. Despite this silver lining, the Dow still ended lower, shedding 41 points, or 0.3%, to end at 15,837.

Walt Disney (DIS 1.52%) lost 0.7% on Monday, even as its animated feature-length film Frozen continues to impress at the box office. Frozen was the fourth-highest grossing film in the U.S. this weekend, and has been a blowout success since its debut 10 weeks ago. The family film has now taken in nearly $350 million domestically, which makes for a tidy profit considering Frozen's $210 million budget. With the worldwide gross around $775 million and growing, it's a blowout success and a tent-pole film for Walt Disney. This is where Disney's girth and diversification hold back its returns; Frozen's success can only do so much for the $125 billion company's stock price.

On the other hand, $1 billion corporations like Noodles & Company (NDLS 7.69%) tend to have a more hyper-focused business model. The newly public company, which has been wildly volatile since its IPO last June, saw shares rally 5.1% Monday. Seven months later, the stock trades for more than twice its $18 IPO price. That said, Wall Street figured Noodles & Company was sold off too steeply last week, when shares tumbled about 7%. It's still tough to value this rapidly growing fast-casual chain, so if you're thinking about investing in this business, make sure you have thick skin and a long-term commitment before you do.

Shares of Millennial Media (NYSE: MM), a mobile advertising solutions platform, also roared higher on Monday, tacking on 9.7%. Although official fourth-quarter results aren't expected until mid-February, Millennial Media shared preliminary results for the fourth quarter that topped the company's previous estimates. Adjusted EBITDA, or earnings before interest, taxes, depreciation and amortization, is expected to fall between $5 million and $6 million, a far cry from the zero to $2 million range given before. The company also announced that its current CEO has resigned, and that former Yahoo! (NASDAQ: YHOO) Chief Revenue Officer Michael Barrett will be filling the slot.