The dollar fell to a 15-month low against the yen on Monday as a renewed slide in oil prices and doubts about the effectiveness of the Bank of Japan's negative interest-rate policy drove investors back into the safe-haven currency. After gaining overnight, crude oil futures again fell, weighing on investor confidence and sapping risk appetite. The surprising announcement that BoJ was cutting its interest rate to minus 0.1 percent on certain deposits sent the dollar up as much as 2 percent on Jan. 29. But markets have since reconsidered, with investors now buying the yen and selling the dollar. Monday's price action ... (full story)