NEW YORK (CNNMoney.com) - U.S. stocks struggled Wednesday morning as investors eyed an earnings warning from DuPont, the second Dow component this week to offer disappointing news.

The Dow Jones industrial average (Charts), the broader S&P 500 (down 0.30 to 1,289.39, Charts) index and the Nasdaq composite (down 1.58 to 2,318.74, Charts) both hovered near unchanged.

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Stocks were mixed Tuesday as investors digested a five-session rally and took in Dow component Alcoa (Research)'s below-forecast earnings.

Trade remained mixed Wednesday as investors took in another earnings blow -- a warning from chemical maker and fellow Dow component DuPont, which said it will miss analysts and its own expectations due to the impact of the two hurricanes last fall and other factors.

DuPont (Research) shares fell 4 percent at the open.

Genentech (Research) shares slumped following the company's earnings report late Tuesday. The drugmaker said sales of its colon cancer treatment Avastin were short of estimates, which overshadowed its higher quarterly earnings that were in line with estimates.

U.S. crude oil for February delivery fell 9 cents to $63.28 a barrel in electronic trading, ahead of the weekly crude oil inventories report, due out at around 10:30 a.m. ET.

Treasury prices rose, lowering the yield on the 10-year note to 4.42 percent from around 4.43 percent late Tuesday. Treasury bond yields and prices move in opposite directions.

The dollar fell versus the euro and yen.

COMEX gold for February delivery lost 70 cents to $545 an ounce.

In global trade, major Asian markets ended higher and European markets rose at midday.