The U.S. dollar briefly plunged to the upper 138 yen level early Friday in Tokyo on speculation that the Bank of Japan could tweak its ultraeasy monetary policy at its meeting ending later in the day. The yield on the benchmark 10-year Japanese government bond hit 0.505 percent, exceeding the upper limit of 0.500 percent set by the central bank, after a news report that the BOJ will discuss a change in its policy to allow long-term interest rates to rise above its cap by a certain degree. The dollar fell by around 2 yen following the news report. At 9 a.m., the U.S. currency fetched 138.88-91 yen compared with ... (full story)