Global ETFs traded down Friday on profit taking and weaker-than-expected export data from China, raising concerns that its economic growth is decelerating. The world's second-largest economy reported export growth slipped to 1% in July from 11.3% in June, owing to weak European demand. Economists expected a 7% gain in July. Gross domestic product grew 7.6% in the second quarter, marking the slowest rate since 2009, and far below the government's