US stock market opens mixed; Yahoo and Dow Chemical are among the early gainers

Stocks are opening mixed as investors look over earnings reports from U.S. companies.

Yahoo rose 6 percent after the Internet company reported a windfall from Alibaba's recent IPO. ETrade and Dow Chemical also rose after reporting earnings that were better than Wall Street analysts were expecting. Biogen and Discover Financial fell.

The Standard & Poor's 500 index rose two points, or 0.1 percent, to 1,943 as of 9:35 a.m. Eastern time Wednesday.

The Dow Jones industrial average fell 13 points, or 0.1 percent, to 16,603. The Nasdaq composite rose four points, or 0.1 percent, to 4,424.

European markets edged higher as investors were hopeful for new stimulus measures from the European Central Bank.

Bond prices fell. The yield on the 10-year Treasury note rose to 2.24 percent.