The S&P 500 gained 4.63 points, or 0.40 percent, to close at 1,150.24, below the 2010 intraday high of 1,150.45 and slightly above the closing high of 1,150.23, both made on January 19.

The Dow Jones Industrial Average closed up 44.51 points, or 0.42 percent, at 10,611.84. The Nasdaq Composite closed up 0.40 percent.

For the next few trading sessions, market participants will watch the S&P 500 closely to see if it can clear above the 2010 high and sustain the rally.

Although the U.S. stock market struggled in the morning session, financials and health care companies carried the stock market into positive territory.

Aetna (NYSE:AET) closed up 3.29 percent and Coventry (NYSE:CVH) closed up 3.37 percent.

Big banks rallied behind Citigroup (NYSE:C), which closed up 5.56 percent. Goldman Sachs (NYSE:GS), JPMorgan (NYSE:JPM), and Wells Fargo (NYSE:WFC) all traded negative at one point but rallied in the afternoon to close up.

Regional banks fared well, with Fifth Third Bancorp (NASDAQ:FITB) closing up 2.47 percent, PNC (NYSE:PNC) closing up 1.81 percent, and U.S. Bancorp (NYSE:USB) closing up 2.04 percent.

At a conference Thursday, Citigroup CEO Vikram Pandit said his firm is well positioned to return to sustained profitability.

Pandit sees potential in Citi's global business, echoing his statements made in the 2009 fourth quarter earnings release.

Citigroup also successfully sold $2 billion in trust preferred securities on Wednesday, indicating a robust market from which similar firms can successfully raise capital.