In the last trading session, U.S. stocks ended on a weaker note thanks to renewed global growth concerns. Among the top ETFs, investors saw SPY go down 1.2%, DIA lose 0.99% and QQQ shed 1.44% 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: IAI: Volume 3.73 times average This U.S. broker-dealer ETF was under the microscope yesterday as nearly 417,000 shares moved hands. This compares to an average trading day of 117,000 shares and came as IAI lost about 3.3% in the session. The movement was due to the dovish Fed minutes as lower rates hamper the income for broking companies. However, the fund has a Zacks ETF Rank #3 (Hold). IAI was down about 3.8% in the past one-month period. EWJ: Volume 2.36 times average This Japan ETF was in focus yesterday as roughly 117.6 million shares moved hands on that day compared to an average of roughly 50.9 million. We also saw some share price movement as shares of EWJ lost 0.5%. The movement can largely be blamed on the strengthening of the yen against the dollar. It could have a big impact on Japan stocks that we find in this ETF portfolio. For the past one month, EWJ was down 3.4%. The fund currently has a Zacks ETF Rank #3 with a Medium risk outlook. 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-US BR-D (IAI): ETF Research Reports ISHARS-JAPAN (EWJ): 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