Following the highest close for the broad-based S&P 500 (^GSPC -0.46%) in five years, it's not surprising to see the index take a breather today, following very mixed earnings results.

Causing the biggest hoopla is the kick-off of money center bank earnings from Wells Fargo (WFC -1.11%). As my Foolish colleague John Maxfield pointed out earlier, Wells Fargo's fourth-quarter and full-year profits were both records, but its net interest margin fell to 3.56%, a 10-basis point drop from the previous quarter, and a 33-basis point drop from the year-ago period. A near-record low in lending rates is putting pressure on Wells Fargo's margins, which could portend poorly for the rest of the finance sector.

For the day, the S&P 500 finished fractionally lower, by 0.07 points (-0.00%), to close at 1,472.05.

Examining some of today's best performers, none shines more brightly than big-box retailer Best Buy (BBY 1.09%), which rose 16% following the release of holiday season sales data. Best Buy shocked analysts to the upside with a 0.4% decline in total sales, a 1.4% ease in same-store sales, and a 10% boost in U.S. online sales, as its focus on tablets and mobile devices, as well as Amazon.com's (AMZN -1.65%) need to collect 4%-6% sales tax in certain states, ultimately boosted sales. Most people on Wall Street have been critical of Best Buy's price-matching turnaround plan, but its focus on mobile and strong cash flow won't put this retailer in the grave just yet.

If misery loves company, then happiness is a party that welcomes all! IT consulting firm Cognizant Technology Solutions (CTSH -1.13%) rallied nearly 5% following Infosys' (INFY -0.18%) third-quarter earnings beat. What was interesting about Infosys' earnings beat was that it occurred in spite of reduced spending in the United States. For Cognizant, which is very much dependent on the U.S. market, this could be good news. I'd keep those expectations tempered, however, as Infosys' outlook wasn't all that rosy.

Rounding out the day's best stocks within the S&P 500 was hospital operator Tenet Healthcare (THC -0.76%), which rallied better than 3% after its CEO, Trevor Fetter, spoke at the JPMorgan Healthcare Conference in San Francisco. Sparking the rally was Fetter's comment that his company's exposure to uninsured persons in Texas and Florida would be reduced dramatically with the implementation of the Affordable Care Act in 2014, which mandates that Americans carry health insurance, and will greatly expand Medicaid coverage. It's very hard to argue against Fetter's analysis, although Tenet remains among my least favorite selections within the sector after its big move higher.