Wednesday’s marquee market event comes in the form of Federal Reserve Chairman Ben Bernanke’s congressional testimony. No one knows for sure what the Fed chief will say, but still fresh on the minds of many traders and investors are Bernanke’s comments last week that assuaged skittish markets that tapering of quantitative easing may not be as imminent as previously thought.

While Bernanke added that interest rates will remain low even if the U.S. unemployment rate falls below 6.5%, his comments about tapering of the Fed’s $85 billion-a-month bond-buying program represents a reversal from commentary delivered in May that sent chills through the bond market and yield-bearing ETFs. [Yield Curve Profits With These ETNs]

Combine the May comments with those delivered last week and it can be said that Bernanke has introduced an element of uncertainty, perhaps modest, ahead of Wednesday’s testimony. At the very least, he has shown he can say one thing one week and something different a few weeks later. [Treasury ETFs in Focus]

For near-term traders, the best course of action might be to simply listen to what markets say. In terms of the U.S. dollar and the PowerShares DB US Dollar Index Bullish (NYSEArca: UUP), currency traders may be tipping their hands that they expect Bernanke to make comments that are supportive for the greenback.

During Wednesday’s Asian session, the dollar is trading sharply higher against its major rivals. At this writing, EUR/USD is down 0.19% while the greenback is up at least 0.3% against the Japanese yen and the Swiss franc. AUD/USD is also lower by 0.3%, though this could be a case of some profit-taking after the Aussie ran higher Tuesday. Then again it, could be the resumption of a bearish trend that has made the Aussie the second-worst performing developed market currency in the world this year behind the yen. [Australia ETFs: Rebound Potential?]

The U.S. Dollar Index is up 0.2%, which could spell good news for UUP as it is the Dollar Index tracking ETF. As for other clues, UUP has raked in $91.1 million in new assets over the past week, making it the fifth-best PowerShares ETF by that metric, according to issuer data. UUP’s bearish equivalent, the PowerShares DB Dollar Bearish (NYSEArca: UDN) has reaped no inflows in the past week.