 Its a new year of trading but its also time to look back at some old seasonal patterns.The US dollar tends to strengthen in January; with an average gain of 0.44 over the past two decades, its the second-best month for the dollar index.Where is the dollar strength:Its the second-worst month for EURUSDIts the worst month for CADCable bucks the trend, as its a decent month for the poundIts the strongest month of the year for gold 