PowerShares DB U.S. Dollar Index Bullish Fund ( UUP) -1% Sweeping market strength is driving investors out of defensive assets such as the U.S. dollar. It has been a rollercoaster week for the greenback as European economic issues continue to dominate investor sentiment. Although safe havens are falling out of favor as we approach the weekend, I would encourage investors to avoid going all in at this point. Rather, looking ahead, there are plenty of hurdles still in the way. Maintaining a line of defense will be crucial to safe navigation. All prices as of 2:14 PM EST Written by Don Dion in Williamstown, Mass.