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 investing thesis.

According to stock index futures as of 7:45 a.m. EDT, the Dow Jones Industrial Average (^DJI 0.40%) will open significantly lower today, falling by 144 points at the opening bell. Major global markets sold off overnight, with European stocks down by 1% and Asian indexes roughly 2% in the red. All eyes are on U.S. lawmakers, who have yet to prevent a government shutdown that would begin at midnight tonight.

A brief shutdown wouldn't matter much to the economy. If it lasts two weeks, it might temporarily shave off 0.3 percentage points from fourth-quarter economic growth, according to Macroeconomic Advisers. The far bigger risk would be a debt-ceiling breach later in the fall, which unfortunately hasn't been ruled out yet by Congress.

With those broader trends in mind, here are a few individual stock stories to watch for in today's market.

It is smartphones over soda after Apple (AAPL -0.35%) unseated Coca-Cola (KO) to become the world's most valuable brand in this year's Interbrand report. Apple's brand value jumped an estimated 28% to $98 billion, knocking Coca-Cola out of the top spot for the first time in 13 years. The beverage giant still boasts an $80 billion brand, though, which was good enough for third place behind Apple and Google. Ironically, Apple's 28% brand boost was the exact opposite of its stock performance, as shares have fallen 28% over the last 52 weeks. Still, as famous value investor Benjamin Graham explained, the stock market is a weighing machine, not a voting machine, over the long run. Apple shareholders can make a good case that their company is getting heavier.

Boeing's (BA 0.25%) Dreamliner worries continue. A 787 plane headed to Poland yesterday was forced to land in Iceland instead after a faulty antenna failed to broadcast the flight's identification information. The issue adds to the Dreamliner's growing list of technical problems, which includes battery malfunctions that have grounded the planes at several airlines. Boeing shares are unchanged in premarket trading.

Finally, AMC Networks (AMCX -4.41%) could buck the negative trend today. Fresh off of the Emmy win and blockbuster finale for Breaking Bad, the company was the focus of a bullish Barron's article over the weekend. Barron's pegs AMC shares as ripe for a 20% rise over the next year as it works to dramatically boost its original content library while keeping costs in check. AMC shares are unchanged in premarket trading.