The yen plunged to its lowest level in nearly four years and showed no signs of slowing its weakening trend in response to the Bank of Japan's latest push to ease monetary policy. Investors have been aggressively selling the Japanese currency since policy makers at the BOJ announced last week they will print trillions of yen to pump money into Japan's sluggish economy in a bid to keep interest rates low and spark faster growth. "Both Japanese and non-Japanese investors appear to be selling Japanese government bonds equally aggressively," said Michael Woolfolk, senior currency strategist at Bank of New York...