Unlike the footballs that the New England Patriots used in the AFC Championship game against the Indianapolis Colts, the U.S. dollar has remained well inflated. The dollar, which has been trending higher for nearly four years now, rose 13% in 2014 and is up another 5% so far in 2015. The latest leg up has been driven by anticipation and arrival of quantitative easing (QE) by the European Central Bank (ECB). Bold stimulus from the ECB, and other central banks around the world including the Bank of Japan, has put substantial downward pressure on the euro, the yen, and other currencies, while boosting the dollar. In general, more supply of a currency drives down its value. In this week’s commentary, we discuss some of the causes of the strong U.S. dollar and some of the most important implications for investors.