In the last trading session, U.S. stocks were mostly in the red. Return of pessimism in the oil patch weighed on these stocks. Among the top ETFs, investors saw (SPY Quick QuoteSPY - Free Report) lose about 0.3%, (DIA Quick QuoteDIA - Free Report) move lower by about 0.4% and (QQQ Quick QuoteQQQ - Free Report) gain just 0.01% on the day.

Two more specialized ETFs are worth noting in particular though as both saw trading volume that was far outside of normal. In fact, in the most recent trading session, both these funds experienced volume levels that were more than double their average. This could make these ETFs ones to watch out for in the days ahead to see if this trend of extra interest continues:

(VGT Quick QuoteVGT - Free Report) : Volume 4.48 times average

This technology ETF was under the microscope on yesterday as nearly 1.5 million shares moved hands. This compares to an average trading volume of 330,000 shares and came as VGT lost about 0.03% in the session.

The movement can largely be credited to the flurry of tech earnings lined up for imminent releases. In the last one-month period, VGT was up about 11.4%. The fund has a Zacks ETF Rank #2 (Buy).

(FHLC Quick QuoteFHLC - Free Report) : Volume 3.74 times average

This healthcare ETF was in focus yesterday as roughly 420,000 shares moved hands compared with an average of roughly 120,000 shares.

After such steep sell-offs, especially in the biotech space, the healthcare space seems to have returned to reasonable valuation. Probably this is why the fund enjoyed outsized volume amid earnings releases.In the last one-month period, FHLC was up over 9.9%. The fund has a Zacks ETF Rank #3 (Hold).

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