On Monday morning, while many in Tokyo enjoyed a public holiday, Yoshio Iguchi was on high alert at Traders Securities Co.’s Shibuya office. The already-jittery currency market was primed for official action aimed at reversing the yen’s slide to a more than three-decade low. Friday’s central bank decision had been unexpectedly dovish and was deemed unlikely to change the currency’s course. Yen bears were galvanized, and the Golden Week holiday meant trading would be thin. The 20-year market veteran was right to be vigilant: At about 10.30 a.m., the yen dropped like a stone. The plunge to 160 per dollar immediately ... (full story)