The S&P 500 fell 0.2% to 1,312.21 at 9:31 a.m. New York time. The benchmark gauge has risen 2.9% this week.
Equity futures joined a global slump as German exports dropped in April for the first time this year as weaker global growth curbed demand.
Investors also watched Europe’s attempts to tame its debt crisis. Spain is poised to become the fourth of the 17 euro-area countries to require emergency assistance as the currency bloc’s finance chiefs plan weekend talks on a potential aid request to shore up the nation’s lenders.
The S&P 500 is headed for its best weekly gain since December 23 as China cut its interest rate and European Central Bank President Mario Draghi said officials stand ready to act.