NEW YORK ( TheStreet) -- Markets have been awaiting Federal Reserve Chairman Ben Bernanke's testimony before Congress on Wednesday.Speculation for hawkish and dovish stances both have validity, which has caused volatile trading on thin volume. With the consensus still that bond purchases will slow this fall, Bernanke's perception of economic data over the past few weeks will determine whether September is still the right time to rein in easing. The first chart below is of PowerShares DB US Dollar Index Bullish ( UUP) over CurrencyShares Swiss Franc Trust ( FXF). This pair crosses the U.S. dollar verus the Swiss franc, a traditional safe-haven currency. The dollar has given up positioning at its yearly highs, due to a dovish tone from the Fed over the past few weeks. Bernanke has reiterated that tighter policy depends on better economic data. His dissatisfaction with labor markets, albeit prior to the latest jobs report, led investors to believe quantitative easing was still on the table for an extended period of time. Bernanke's testimony should determine whether the Fed is pleased with improvements in data seen the past few weeks, thus giving more weight to the idea of a slowdown in bond purchases starting in September.