In the last trading session, U.S. stocks ended on a weaker note, owing to a slump in oil prices and disappointing earnings results. Among the top ETFs, investors saw SPY go down 0.17%, DIA slump 0.2% but QQQ remain broadly unchanged 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: FENY: Volume 2.44 times average This energy ETF was in focus yesterday as around 430,000 shares moved hands compared with an average of roughly 179,000 shares a day. We also saw some price movement as FENY lost nearly 1.1% in the last session. The big move was largely the result of a weaker oil price following a report that showed a spike in U.S. crude inventory. This can have a big impact on energy stocks like what we find in this ETF portfolio. FENY was up 7.8% over the past one month and currently has a Zacks ETF Rank #5 (Strong Sell). TLO: Volume 2.23 times average This long-term government bond ETF was in the spotlight yesterday as almost 409,000 shares moved hands. This compares to an average trading day of 189,000 shares. TLO was down about 0.3% in the session. The movement can largely be blamed on the rise in long-term treasury yields while investors continue to await the conclusion of a Federal Reserve policy meeting later in the week. TLO fell 1% in the past one-month period. The fund currently has a Zacks ETF Rank #2 (Buy) and may be interesting for longer-term investors. 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 FID-ENERGY (FENY): ETF Research Reports SPDR-BC LT TRS (TLO): ETF Research Reports SPDR-SP 500 TR (SPY): ETF Research Reports NASDAQ-100 SHRS (QQQ): ETF Research Reports SPDR-DJ IND AVG (DIA): 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