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.

Stock markets took a bit of a breather this week, with the Dow Jones Industrial Average (DJINDICES:^DJI) falling 1.49% and the S&P 500 (SNPINDEX:^GSPC) slipping 1.08%. There wasn't a lot of economic news, but Federal Reserve officials did continue hinting that they'll slow an $85 billion bond-buying program later this year depending on economic conditions. Short-term, the Fed's actions will keep markets volatile, but investors should remember that the Dow is up 17.7% so far this year and the S&P 500 is up 18.6%, so small pullbacks like we had this week aren't the end of the world.

Alcoa (NYSE:AA) was the biggest gainer this week, jumping 3.5%. The big driver was a report showing a 9.7% increase in China's factory output in July. Alcoa is very dependent on growing demand from China, one of the few places in the world where there's significant growth. There's been a lot of concern that China's growth will slow so Alcoa will tend to jump whenever there's positive data.  

Microsoft (NASDAQ:MSFT) was a surprise winner on the Dow this week, moving 2.5% higher. The stock has been moving steadily higher after an earnings disappointment, and this was just another step in that direction. Analysts at Evercore upgraded the stock to overweight and upped their price target to $38, causing a jump on Thursday, but the bigger story may be the slow and steady progress the company is making in tablets. Japanese insurer Meiji Yasuda Life Insurance announced a 30,000-unit Surface purchase, and research firm IDC announced that Microsoft's tablet market share rose to 4.5% in the second quarter from 1% a year ago. At least it's a step in the right direction, and it's a positive considering the strength in Microsoft's other businesses.

UnitedHealth Group (NYSE:UNH) rounded out the top three stocks on the Dow after climbing 0.9% this week. There wasn't a lot of news out about the company, but when markets fall, health-care stocks can often be a safe haven. Investors are also becoming increasingly comfortable that profits will remain strong after Obamacare takes hold. The company gained 12.6 million customers over the past year through organic growth and acquisitions and has strong earnings momentum, which should keep this stock moving higher despite cost pressures.

Fool contributor Travis Hoium owns shares of Microsoft. The Motley Fool recommends UnitedHealth Group and owns shares of Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.