US indices closed lower last Friday amid sharp decline in tech stocks. One example is Amazon, which posted a massive 7.6% decrease in shares, the largest downswing it had since May 2020.

The company reported that its sales fell short of expectations, and this contributed to Nasdaq 100 and S&P 500 slipping in value last Friday. S&P 500 lost around 0.4%.

Other tech stocks, including Microsoft, pushed the DJIA down as well.

Markets were also affected by tighter regulations in China, rising incomes and the potential for new stimulus. Amazon's sales outlook complements cautious forecasts by Facebook and Apple, which fuels controversy on whether tech stocks rallies linked to the pandemic will succumb to a cyclical rebound.

In any case, the earnings reports this second quarter have been stronger than expected. Bloomberg said more than 80% of S&P 500 companies reported sales that exceeded forecasts, but this did not ease investor concerns on another deep downturn. There is another outbreak because of the delta strain of the coronavirus, not to mention there is a crackdown in China's private technology firms.

"When you reach the valuation level at which we are, professional investors are looking for a reason to sell. It could be a delta option, or it could be China. But it doesn't matter. Investors are looking for a reason to sell because they know the appraisals have been extended and they don't want to be the last to hold the bag," David Spica, CIO of GuideStone Capital Management, said.