The latest from Goldman Sachs:
We became Dollar bulls in April 2014, forecasting that the greenback would rise 15 percent against the majors. We reasoned that slack was diminishing, allowing the Fed to normalize monetary policy, which would move rate differentials in favor of the Dollar. In the event, the Dollar rose more and faster than we expected, but for a different reason. BoJ and ECB pursuit of QE drove the Dollar up, while the Fed has done little to normalize policy, amid signs that it is increasingly targeting the currency (Exhibit 1).
