In the last trading session, U.S. stocks ended on a weaker note as oil prices slumped ahead of oil producers’ Doha meeting on Sunday to freeze output. Among the top ETFs, investors saw SPY go down 0.11%, DIA lose 0.16% and QQQ shed 0.25% 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 recent trading session. This could make these ETFs the ones to watch out for in the days ahead to see if this trend of extra-interest continues: TLH: Volume 10.18 times average This long-term U.S. treasury ETF was in focus on Friday as roughly 1.2 million shares moved hands compared to an average of roughly 119,000 shares. We also saw some stock price movement as shares of TLH advanced over 0.4%. A plunge in long-term bond yields following a flight to safety favored the long-term U.S. treasury bonds like what we find in this ETF portfolio. The fund has a Zacks ETF Rank #3 (Hold). However, in the last one month, TLH was up about 2%. XPP: Volume 4.22 times average This leveraged China ETF was under the microscope on Friday as nearly 97,000 shares moved hands. This compares to an average trading volume of 23,000 shares and came as XPP lost 2.8% in the session. The big move can largely be blamed on China posting disappointing GDP growth for the first quarter of 2016. In the last one-month period, XPP was up about 8.5%. Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ISHARS-10-20YTB (TLH): ETF Research Reports PRO-ULT FT CH25 (XPP): ETF Research Reports SPDR-SP 500 TR (SPY): ETF Research Reports SPDR-DJ IND AVG (DIA): ETF Research Reports NASDAQ-100 SHRS (QQQ): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report