The Dow Jones Industrials (^DJI 0.28%) gained almost 59 points on Friday, managing to give the Dow a small gain of just over 20 points on the week. Yet, even though positive contributions from ExxonMobil (XOM 0.94%) and Microsoft (MSFT -1.35%) helped keep the Dow moving higher, Visa's (V -1.08%) substantial drop reflected some of the uncertainties in investors' minds about how much further consumer spending can take the stock market.

Visa's fall of 1.7% came on the heels of a lawsuit from retail giant Wal-Mart (WMT 0.15%), seeking $5 billion in damages concerning the credit card network's policy on swipe fees. The move had been long anticipated, given that Wal-Mart and many other major retailers had chosen not to participate in a class action lawsuit that led to a $5.7 billion settlement that Visa and MasterCard paid to thousands of smaller retailers. Given Visa's growth in recent years, the company should be able to afford to resolve the dispute relatively amicably at some point in the future if it wants to, but in the meantime, it will be interesting to see whether Wal-Mart's allegations of antitrust violations actually gain traction in a court proceeding.

ExxonMobil, on the other hand, gained 1.5%, adding to its similar-sized jump Thursday following optimistic comments about the oil giant from Merrill Lynch. Analysts at Merrill upgraded Exxon stock, pointing to relatively low valuations compared to the broader market's earnings multiples. Of course, one issue pointing the other way is that Exxon has struggled to produce growth lately, with sluggish prices and production actually threatening to make profits contract in the near future. Still, as other stocks in the Dow have climbed even more dramatically during the past year or two, Exxon starts to look more attractive by comparison, especially as investors start to hope that economic sanctions against Russia won't hamstring the oil giant's profit potential.

Finally, Microsoft finished the day up 2.4%. Most investors focused on the company's initiative to make its Office software available on the iPad this week, but Microsoft's long-term success relies on much more than a single product -- even one as important as Office. Rather, the big question that Microsoft investors have to answer is whether they believe that new CEO Satya Nadella can lead the tech behemoth in a better direction after years of what many saw to be stagnation. So far, just the appearance of promising changes has been enough to inspire long-term investors about the potential for gains at Microsoft; but after Nadella's honeymoon period ends, Microsoft will have to show that his efforts have actually borne fruit in the form of sales and earnings growth.