The currency market remains caught in the crosscurrents of a growing wave of dollar selling -- or speculation about it -- and fears of central bank intervention.

The Bank of Japan intervened in the currency market for the first time in nearly six months last month. The BOJ stepped in when the greenback fell below 124 yen on May 23 and has since returned to the market repeatedly to keep the dollar from falling further.

Politicians and Finance Ministry officials appear obsessed with the bitter memory of 1999, when a strong yen fueled by foreign investors' increased purchases of Japanese stocks put the brakes on the nation's exports and stifled a nascent economic recovery.