Dollar slide heightens alert for yen intervention Forbes - May 8 ... trading was jittery and at times rumor-driven as the dollar slipped below a key area between 116.40 and 116.30 yen, where analysts said the Bank of Japan would become more likely to act and buy dollars on behalf of Japan's Ministry of Finance ... 116.0 mark have taken it within sight of an oft-cited "line in the sand" where many traders expect Japan would be forced to step in. "A break of 115.0 yen would be very ominous," said Marc Chandler, chief currency strategist with HSBC in New York.