NEW YORK — Wall Street is stumbling toward the finish line of a fourth straight losing week on Friday, but an ease in oil prices is taking some of the pressure off stock markets worldwide.

The S&P 500 fell 0.5% in early trading and was on track for its longest weekly losing streak in a year. The Dow Jones Industrial Average was down 126 points, or 0.3%, as of 9:35 a.m. Eastern time, and the Nasdaq composite was 0.8% lower.

U.S. stocks slipped under the weight of another rise for yields in the bond market. That makes borrowing more expensive for U.S. companies and households, slowing the economy, and it grinds down on prices for all kinds of investments. Treasury yields have been climbing since the war with Iran began because it could…