A trader works on the floor during the Slack Technologies Inc. IPO at the New York Stock Exchange (NYSE) in New York, June 20, 2019.

Check out the companies making headlines after the bell:

Beyond Meat fell 4.52% toward the end of extended trading after news that a consumer group, the Center for Consumer Freedom, launched an ad campaign alleging many plant-based meat products could include traces of toxic chemicals. Breanne Kincaid, the center's research director, told CNBC's "Fast Money" Thursday that some plant-based meat products are exposed to a chemical called Hexane when it is being processed. The group doesn't know if the chemical is used in Beyond Meat's product.

Beyond Meat declined to comment on the campaign. The company is in a mandatory quiet period prior to their quarterly report. The Federal Drug Administration allows Hexane to be present in food under certain conditions.

Shares of PayPal fell 1.27% in extended trading after the digital payments company announced that COO Bill Ready will leave at the end of the year. PayPal hit a new 52-week high during market hours on Thursday. The company said Ready will be pursuing entrepreneurial opportunities.

"Bill will continue to work with key partners and our leadership team until the end of the year," PayPal CEO Dan Schulman said in a statement. "I appreciate his commitment to PayPal and its future."

Slack Technologies continued to climb after hours, gaining 2.62%. The enterprise communications company's stock rose 48.54% intraday following its direct listing and market debut on the New York Stock Exchange.

CrowdStrike slipped 2.14% after hours, bringing the stock down to about $73. The cybersecurity company went public last week, originally pricing its shares at $34. The stock nearly doubled during its first day of trading.