In the last trading session, U.S. stocks demonstrated an encouraging performance thanks to the surge in oil prices. Among the top ETFs, investors saw SPY gain 0.27%, DIA surge 0.20% but QQQ rise 0.32% 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:

(PTH Quick QuotePTH - Free Report) : Volume 3.78 times average

This healthcare ETF was in focus yesterday as nearly 50,000 shares moved hands. This compares to an average trading volume of 13,500 shares and came as PTH gained 0.3% in the session.

The movement can be attributed to the slew of earnings beats reported by the companies in the sector that can have a big impact on the healthcare stocks like what we find in this ETF portfolio. In the last one-month period, PTH was up about 8%. The fund has a Zacks ETF Rank of 2 or ‘Buy’ rating with a High risk outlook.

: Volume 2.46 times average

This oil ETF was in focus in the last trading session as around 6.4 million shares moved hands compared with an average of roughly 2.6 million shares a day. We also saw some price movement as OIL gained nearly 3.43% in the last session.

The big move came in as crude oil jumped as U.S. government stated that stockpiles of gasoline shrank by more than 3 million barrels last week. In the past one-month period, OIL was down approximately 19.6%.

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