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Investors had hoped that positive earnings momentum would continue to drive stocks higher, but this morning's figures from two major components of the Dow Jones Industrials (^DJI -0.98%), as well as a negative warning from Best Buy, sent the blue-chip index down 91 points as of 11 a.m. EST. UnitedHealth Group (UNH 1.35%) and Goldman Sachs (GS -0.71%) both fell after giving their earnings reports, offsetting a gain from McDonald's (MCD -0.42%) based on encouraging industry figures.

UnitedHealth dropped 3.3% even though the health insurer added 4.5 million members during 2013 and posted an 8% jump in revenue for the fourth quarter, pushing earnings up 15%. Success in its Optum segment also added to the company's bottom-line gains, with operating earnings jumping 43% for the pharmacy-benefits and consulting-services division. UnitedHealth also confirmed its previous guidance for revenue and earnings for 2014, but investors remain concerned about the potential for cuts in government program reimbursement rates and the potential impact on UnitedHealth's profits.

Goldman Sachs dropped 1.8% as the bank reported that profits fell 21% in the fourth quarter compared to the year-ago period, on a 5% drop in overall revenue. Goldman's investment-banking division was particularly successful, seeing profits rise by 22%. But trading results from the fixed-income and other markets hurt Goldman overall, as revenue from client trading fell 15%; a drop in bond-underwriting activity also contributed to the fall. Despite the falling share price, Goldman's results were actually better than most investors had expected. But with the likelihood of continuing pressure on the bond market, Goldman could keep struggling because of its traditional reliance on fixed income as an area of strength.

McDonald's gained 0.5% after the National Restaurant Association said late yesterday that it projects restaurant-industry revenue to grow 3.6% from 2013 levels. With expectations of $683 billion in sales for 2014, the gains are expected to come primarily from raising menu prices. Moreover, with higher labor costs and upward pressure in food prices for commodities such as beef, McDonald's will have to work hard to turn any added revenue into bottom-line growth. Nevertheless, McDonald's expects to come out with a slate of new products and promotional offerings to try to bolster sales and boost its overall results this year.