In the last trading session, U.S. stocks ended on a mixed note ahead of the inflation data. Among the top ETFs, (SPY Quick QuoteSPY - Free Report) lost 0.1% and (DIA Quick QuoteDIA - Free Report) added 0.1%, while (QQQ Quick QuoteQQQ - Free Report) moved 0.3% 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.

: Volume 7.10 Times Average

This defensive ETF was in the spotlight as around 158,000 shares moved hands compared with an average of 25,000 shares a day. We also saw some price movement as DEF added 0.3% in the last session.

The move was largely due to bouts of volatility and uncertainty in the stock market that raised the appeal for defensive investment and could have a big impact on defensive ETFs like the ones we find in this ETF portfolio. DEF has gained 4.8% over the past month and has a Zacks ETF Rank #3 (Hold) with a Medium risk outlook.

(PRFZ Quick QuotePRFZ - Free Report) : Volume 3.66 Times Average

This small-cap ETF was under the microscope as nearly 436,000 shares moved hands. This compares with an average trading volume of roughly 120,000 shares and came as PRFZ added 0.9% in the last trading session.

The movement can largely be blamed on beaten-down prices after a massive sell-off early this year. PRFZ has gained 9.5% in a month’s time and has a Zacks ETF Rank #3 with a Medium risk outlook.