Stocks have rebounded nicely after a brutal sell-off last week. However, with rising trade tensions and slowing global growth, investors have been pouring a lot of money into quality ETF. These ETFs hold stocks with excellent earnings records and strong balance sheets. Such stocks hold up rather well during market swings.Many academic studies have demonstrated that high quality companies--as determined by factors such as high earnings quality and low leverage-- consistently deliver better risk adjusted returns than the broader market over the long term.An academic paper " Quality Minus Junk " studied quality stocks--defined as those with high profits, high growth, low risk, and high payouts, and found that these stocks yield above-average risk-adjusted returns. The study was based on a broad sample of stocks covering 24 developed countries between 1986 and 2012.To learn more about the iShares Edge MSCI USA Quality Factor ETF (QUAL), the Invesco S&P 500 Quality ETF (SPHQ) and the SPDR MSCI USA StrategicFactors ETF (QUS), please watch the short video above.Top holdings in these ETFs include high quality stocks like Apple (AAPL). Microsoft (MSFT), Johnson & Johnson (JNJ), Facebook (FB) and Mastercard (MA)Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Facebook, Inc. (FB): Free Stock Analysis Report Johnson & Johnson (JNJ): Free Stock Analysis Report Apple Inc. (AAPL): Free Stock Analysis Report Microsoft Corporation (MSFT): Free Stock Analysis Report SPDR MSCI USA StrategicFactors ETF (QUS): ETF Research Reports Invesco S&P 500 Quality ETF (SPHQ): ETF Research Reports Mastercard Incorporated (MA): Free Stock Analysis Report iShares Edge MSCI USA Quality Factor ETF (QUAL): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report