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 Industrial Average (^DJI 0.01%) had an amazing year in 2013, as it soared to an all-time high, posting its highest single-year return since the red-hot days of the '90s. Then 2014 came around, and stocks clumsily skid into the New Year; at one point the Dow was off more than 1,000 points from its fresh record. The roller coaster ride continued today, as the Dow advanced for a fourth straight day, adding 192 points, or 1.2%, to end at 15,994. The index is up more than 550 points in the last four sessions.

Dow component Wal-Mart Stores (WMT 0.83%) was a clear beneficiary of the renewed bullish attitude on Wall Street today, gaining 1.4% in trading. The new chair of the Federal Reserve, Janet Yellen, lured the bulls out Tuesday with her testimony before Congress -- her first as the central bank's head honcho. She expressed solidarity with the outgoing Fed leader, Ben Bernanke, saying the Fed would continue to taper the stimulus but keep interest rates low. Wal-Mart, as one of the largest companies in the world, stands to benefit from a steady economy in which consumers remain price-conscious. 

J.C. Penney (JCPN.Q) faces a far tougher road ahead; the company is still feeling the hurt from Ron Johnson's failed turnaround efforts, in which the former Apple executive eliminated sales and alienated core customers. That nightmare may finally be reversing itself, as J.C. Penney just reported long-awaited holiday sales figures. While official fourth quarter results won't be out for a few more weeks, same-store sales growth in November and December came in at 3.1%. Shares jumped yesterday and are up another 4.9% today as investors count their lucky stars that there actually was sales growth. Next up: restore profitability. 

Lastly, Walgreen (WBA 0.50%) stock surged 5.9% today, reaching a 52-week high during its trading session. Walgreen is generously extending an offer for Americans recently insured under the Affordable Care Act: the pharmacy will give customers with new insurance coverage 30 days' worth of prescriptions at no upfront cost through April 15. The program originally ran through the end of January, but because of Obamacare adoption rates and gaffes with new health insurance coverage, Walgreen is extending the promotion. It's a clever way to lock in new customers and with rival pharmacies scrambling for loyal customers, Walgreen is on the right track.