Japan is on alert against speculative yen moves against the U.S. dollar and is ready to act again in the currency market if needed, the finance minister said Monday, after what is estimated to be the largest-ever daily yen-buying intervention had a "certain effect."Finance Minister Shunichi Suzuki said the government is "strongly concerned" about one-sided, rapid yen moves. Bank of Japan Governor Haruhiko Kuroda also said such currency fluctuations are not desirable and backed Japan's first intervention to prop up the currency since 1998 as "appropriate."Thursday's yen-buying, dollar-sellin…READ FULL ARTICLE