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 Industrials (^DJI 1.18%) responded negatively to concerns that the European economy might not recover as quickly as some had hoped. Despite relatively strong economic data showing some success in the U.S. services industry, the Dow dropped 40 points just before 11 a.m. EST. Verizon Communications (VZ -0.10%) and Walt Disney (DIS 0.92%) were among the stocks leading the Dow lower, while Microsoft (MSFT 2.22%) helped limit the average's losses.

Verizon fell 1.1% as the company's shares responded to news from T-Mobile that it had added 648,000 net subscribers during the quarter, beating expectations almost by half. Verizon's wireless division still posted bigger subscriber growth at 927,000, but T-Mobile outpaced Verizon on phone-subscription growth. Despite its strong leadership position, Verizon can't afford to stop pushing forward with its own innovations as its rivals become better-organized and stronger financially.

Disney declined 0.5% despite seeing a good opening weekend internationally for its Thor sequel release. The success of Lionsgate's Ender's Game science-fiction film could pose a short-term threat to Thor: The Dark World. But despite all the hype that major motion-picture releases get, Disney's major film-production franchises will make dozens of blockbuster films in future years, making the results of any one particular installment less important than headlines give credit. Disney appears well-poised to prosper from demand for content well into the future.

Microsoft rose 1.5% on news that the company would make its Unity game-development engine available to game developers free. The move bolsters the value of Microsoft's broader program to reach out to developers in anticipation of the Xbox One launch, as the software giant hopes that by encouraging more participation in its ID@Xbox program, it can create partnerships with developers to produce a greater volume of games for the platform. That could help Microsoft get an advantage over the PlayStation 4 in the battle of rival consoles.