NEW YORK ( TheStreet) -- U.S. stocks fell Thursday as eBay ( EBAY) and UnitedHealth Group ( UNH) posted first-quarter earnings that fell short of expectations, fueling concerns about the U.S. economic recovery. The S&P 500 lost 0.7% to close at 1,541.61. Google ( GOOG) rose in after-market trading as the Internet search leader's quarterly results beat estimates. Shares were moving higher by 1.3% to $776.17. EBay dropped 5.9% to $52.82 after the e-commerce giant provided second-quarter guidance Wednesday that fell short of analysts' estimates and posted first-quarter results that fell well short of expectations. UnitedHealth Group lost 3.8% to $59.69 after the biggest U.S. health insurer stood by its full-year earnings forecast of $5.25 and $5.50 a share but warned of lower revenues due to changes in the sales relationship with a "very large" public-sector customer. Pepsico ( PEP) jumped to its highest since 1980, adding 3% to $81.25 after the snacks and beverages giant posted first-quarter earnings that beat estimates by six cents as higher prices contributed to an increase in profit margins. Morgan Stanley ( MS) lost 5.4% to $20.33 on concerns the New York-based bank's investment and trading businesses trail competitors. Morgan Stanley's first-quarter profit did beat analyst expectations as the bank reported net income of 61 cents a share on revenue of $8.5 billion compared to forecast for earnings of 57 cents a share on revenue of $8.35 billion. Written by Andrea Tse and Joseph Deaux in New York >To contact the writer of this article, click here: Andrea Tse.