The Dow Jones industrial average moved between small gains and losses Friday morning. It was down 16 points at 15,066 as of noon Eastern Daylight Time. Other indexes rose slightly.
The Dow is up 0.6 per cent for the week and 15 per cent so far this year.
Prices for commodities including crude oil and gold fell sharply as the dollar continued to strengthen against other currencies, especially the Japanese yen.
Priceline.com and chipmaker Nvidia rose sharply after reporting higher earnings.
The Standard & Poor's 500 index was up a fraction of a point at 1,627.
The Nasdaq composite was up 12 points at 3,421.