The U.S. stock market suffered its worst week (ending July 24) in months thanks to disappointing earnings results, especially from Apple (AAPL), Caterpillar (CAT) and International business Machines (IBM) as well as a string of bleak sales or earnings outlook (read: 4 ETFs to Watch Post IBM 2Q Results).

This is especially true as total earnings for the S&P 500 companies that have reported so far are up 3.6% on an annual basis with a beat ratio of 73.3% while revenues have increased 0.9% with a beat ratio of 50.8%, as per the Zacks Industry Trend. While the beat ratios are better than the recent quarters, the earnings and revenue growth rates are much lower than Q1 and the four-quarter average.

Additionally, weak PMI data stretching from China to Europe, collapse in commodities and a fresh signs of slowdown in China have renewed worries about global economic growth, resulting in risk-off trade. An unexpected drop of 6.8% in new U.S. home sales for June, strong dollar and the potential for a rates hike sometime later in the year added to the list of woes.

In such a backdrop, the largest and ultra-popular SPDR S&P 500 (SPY – ETF report), tracking the S&P 500 with an asset base of around $$178.9 billion and average daily volume of more than 109 million shares, pulled out nearly $5 billion from its asset base last week, according to data compiled by etf.com. Meanwhile, the Dow Jones proxy – SPDR Dow Jones Industrial Average ETF (DIA – ETF report) – saw less than a billion dollar outflow (see: all the Large Cap ETFs here).

Given the huge outflows and weak fundamentals, the Dow Jones saw the worst weekly loss since January, tumbling nearly 3%. The S&P 500 and the Nasdaq Composite Index too dropped over 2%, marking the biggest weekly declines since March for both indices.

The terrible trading has spread to the equity ETF world as well with a number of products piling up huge losses in last week. Below, we have highlighted the five worst performing unleveraged funds of the week that went by. These funds are expected to continue their rough trading in the weeks ahead if the same trends persist.

First Trust ISE-Revere Natural Gas Index Fund ((FCG – ETF report)) – Down 10.8%

This product offers exposure to the U.S. stocks that derive a substantial portion of their revenues from the exploration and production of natural gas. It follows the ISE-REVERE Natural Gas Index and holds 30 stocks in its basket that are well spread out across components with none holding more than 4.44% share (read:4 Worst Performing U.S. Equity ETFs So Far in 2015).

The fund has amassed $186.5 million in its asset base while charging 60 bps in annual fees. Volume is solid with more than 883,000 shares exchanging hands per day on average. The ETF plunged 10.8% last week and has a Zacks ETF Rank of 4 or ‘Sell' rating with a High risk outlook.

PowerShares S&P SmallCap Energy Fund ((PSCE – ETF report)) – Down 10.1%