Copper retreated from an earlier five-week high on Monday, snapping a four day rally as the struggling dollar strengthened and a strong aftershock in Japan unnerved some investors. COMEX May copper shed 4.15 cents to settle at $4.46 per lb, near the bottom of its $4.4555 to $4.5330 session range.
Trading volumes remained brisk. More than 50,500 lots exchanged hands by 2:25 pm EDT (1825 GMT), in excess of 20 percent above the 30-day norm, according to Thomson Reuters preliminary data.