These stocks were the most stretched heading into the sell-off

Workers near a cruise ship of the Norwegian Cruise Line which is in dry dock receiving hull maintenance and interior modernization work.
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The S&P 500 slumped for a third straight day Thursday on rising fears of a second wave of the virus, weighed by a sharp pullback among the reopening trades. From a technical perspective, the reversal was bound to happen as the rally in many names had gone too far, too fast.

Here are the 20 S&P 500 stocks looking the most frothy heading into the big sell-off Thursday, based on their distance above their 50-day moving average.