Japanese automakers down sharply on yen fears Shares in Asia drifted lower Friday, as investors largely held fire ahead of guidance from U.S.Federal Reserve Chairwoman Janet Yellen. Yellen is speaking later in the global trading day at the Jackson Hole gathering of central bankers. In Japan, the Nikkei Stock Average was down 0.9%, with automobile and insurance stocks hurt by expectations that Yellen would deliver gloomy news about the U.S. economy. That would push down bond yields and weaken the dollar. Lower yields reduce insurers' returns. A weaker dollar pushes the yen higher, hurting export competitiveness. ... (full story)