In the last trading session, the U.S. stocks managed to hold onto modest gains amid mixed economic reports. Among the top ETFs, investors saw (SPY - ETF report) gain 0.6%, (DIA - ETF report) move higher by 0.5% and (QQQ - ETF report) gain 0.8% 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 ones to watch out for in the days ahead to see if this trend of extra-interest continues:

(PBS - ETF report): Volume 3.98 times average

This media ETF was in focus yesterday as about 321,000 shares moved hands compared to an average of over 85,000 shares. We also saw some price movement as PBS gained 1.25% in the past session.

The movement can largely be attributed to positive developments by Walt Disney Company (DIS) that led to optimism in the broad media space and the stocks like the ones we find in this ETF portfolio. For the past one-month period, DIS was down nearly 6.6%. The fund currently has a Zacks ETF Rank #2 (Buy) and may appeal to long-term investors.

(FPA - ETF report): Volume 2.85 times average

This Asia Pacific ex-Japan ETF was under the microscope yesterday as more than 70,000 shares moved hands. This compares to an average trading day of around 25,000 shares and came as FPA shed 0.45% in the session.

The big move was largely the result of cooling demand in China that is weighing heavily on trade in the Asia-Pacific region. FPA lost 3.7% in the past month and currently has a Zacks ETF Rank #3 (Hold).