In the last trading session, Wall Street offered a mixed performance. Among the top ETFs, SPY lost 0.17%, DIA added 0.19% and QQQ moved about 0.8% lower 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.VGIT : Volume 3.87 Times AverageThis intermediate treasury ETF was in the spotlight as around 7.69 million shares moved hands compared with an average of 1.99 million shares a day. We also saw some price movement as VGIT lost 1.1% in the last session. VGIT was up 12.1% over the past month.FDN: Volume 3.16 Times AverageThis internet ETF was under the microscope as nearly 1.9 million shares moved hands. This compares with an average trading volume of roughly 604,000 shares and came as FDN gained 0.4% in the last trading session. FDN was up 10.6%.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week.Get it free >> Want key ETF info delivered straight to your inbox? Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week.Get it free >>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 Invesco QQQ (QQQ): ETF Research Reports SPDR S&P 500 ETF (SPY): ETF Research Reports SPDR Dow Jones Industrial Average ETF (DIA): ETF Research Reports First Trust Dow Jones Internet ETF (FDN): ETF Research Reports Vanguard IntermediateTerm Treasury ETF (VGIT): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research