In the last trading session, U.S. stocks were in the green on anticipation that the testimony from former FBI chief James Comey will cause less upheaval to the market than earlier thought. Among the top ETFs, investors saw SPY and DIA gain about 0.2% each and QQQ move higher by about 0.4% on the day.

Two more specialized ETFs are worth noting as both saw trading volume that was far outside of normal. In fact, both these funds experienced volume levels that were more than double their average for the most of the last trading session. This could make these ETFs ones to watch out for in the days ahead to see if this trend of extra-interest continues:

AMU: Volume 3.65 times average

This MLP ETN, which gives exposure to about 50 publicly-traded energy MLPs, was in the spotlight yesterday as nearly 200,000 shares moved hands compared with an average of roughly 55,000 shares a day. We also saw some price movement as AMU lost about 2.1% in the last session.

The move was largely the result of a steep slide in crude prices on massive U.S. inventory build. AMU has been down about 5.9% in the last one month.

(UCO Quick QuoteUCO - Free Report) : Volume 2.51 times average

This double leveraged oil ETF was under the microscope yesterday as about 19 million shares moved hands. This compares with an average trading day of around 7.62 million shares and came as UCO lost about 10.2% in the session.

The movement can largely be credited to the same oil price decline. Investors should note that WTI crude ETF (USO Quick QuoteUSO - Free Report) lost about 5% on Wednesday. UCO has lost over 5% in the last one month.

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