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.

Boy, the Federal Reserve really threw Wall Street a curveball today. A curveball, incidentally, that Wall Street promptly belted to the parking lot. With the market bracing for a $10 billion or so reduction to the monthly $85 billion bond-buying program, the Fed instead decided that the $85 billion number was just fine. The decision sent nearly every single stock in the Dow Jones Industrial Average (DJINDICES:^DJI) soaring, and the index ended up 147 points, or 1%, at 15,676, an all-time high. 

With the entire materials sector up 2.2% today, Alcoa (NYSE:AA) shares tagged along for the ride, jumping 3.6% Wednesday. Shares are about 90% more volatile than the overall market, so you can usually count on an outsized move from stock in the aluminum giant on big swing days like today. Investors are hoping a continued Fed stimulus will buoy industry, which in turn would be a huge boon to Alcoa.

Of course, homebuilders and stocks associated with the health of the real estate market didn't do too badly either today. Home Depot (NYSE:HD), for instance, rallied 2.1%, continuing to post outsized gains in a year that's already seen the stock jump 25%. The Fed wants to keep interest rates low, in part to keep real estate on the up-and-up, which would be welcome for this home improvement retailer.

Coca-Cola (NYSE:KO), which rewards investors to the tune of a 2.8% dividend each year, added 2.1% Wednesday. Solid companies -- and there may not be a better example of a solid company than the 127-year-old Coke -- with sustainable, decent dividends were bid higher today as bond yields fell on the Fed's announcement. It makes sense that investors would rather have equity in a great company on top of an income stream as opposed to no equity mixed with comparable yields. 

Lastly, UnitedHealth Group (NYSE:UNH) ended the day as the Dow's sole, lonely decliner, shedding 1.7%. Like Alcoa, the health insurer's move today harkens to yesterday's market dynamics, when UnitedHealth was again the weakest performer in the index. The volatility is somewhat understandable: With the all-important Oct. 1 (the day Obamacare state exchanges officially open for business) date looming, some shareholders who've been along for the stock's 34% surge in 2013 may be looking to cash out before the uncertainty rears its head. For long-term investors, it might be worth waiting until October to see how Obamacare factors in to UnitedHealth's business model.

Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter, @divinebizkid, and on Motley Fool CAPS, @TMFDivine.

The Motley Fool recommends Coca-Cola, Home Depot, and UnitedHealth Group. 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.