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.