The yen sank to the upper 156 level against the U.S. dollar Friday in Tokyo, with fears of intervention by Japanese authorities allowing the U.S. currency to briefly drop roughly two yen after the Bank of Japan left unchanged its current monetary easing policy.At 5 p.m., the dollar fetched 156.70-71 yen compared with 155.59-69 yen in New York and 155.62-64 yen in Tokyo at 5 p.m. Thursday.The euro was quoted at $1.0729-0730 and 168.13-17 yen against $1.0725-0735 and 166.94-167.04 yen in New York and $1.0720-0721 and 166.83-87 yen in Tokyo late Thursday afternoon.The yen dropped to as low as …READ FULL ARTICLE