Why Nabors Industries, PolarityTE, and Evolus Slumped Today

The stock market had a mildly positive day on Friday, and gains of between 0.1% and 0.3% were common for most of the major benchmark indexes. Without any outright hostility among leaders of the G-7 nations in their summit in Canada's Quebec City, investors seemed content to go into the weekend with confidence in the prospects for the U.

S. economy and its biggest businesses. Yet some individual companies had bad news that held their shares back from participating in the rally. Nabors Industries (NYSE: NBR), PolarityTE (NASDAQ: COOL), and Evolus (NASDAQ: EOLS)were among the worst performers on the day. Here's why they did so poorly.