Facebook Chief Executive Mark Zuckerberg walks past members of the news media as he enters the office of U.S. Senator Josh Hawley (R-MO) while meeting with lawmakers to discuss “future internet regulation on Capitol Hill in Washington, September 19, 2019.Joshua Roberts | ReutersCheck out the companies making headlines in midday trading:Facebook – Shares of the social media company fell 1.5% as the Department of Justice is reportedly planning to launch an anti-trust investigation into Facebook. This would be the fourth antitrust probe into Facebook, as the company is currently facing probes from the Federal Trade Commission, the House of Representatives Judiciary Committee, and a group of state attorneys general.Square – Shares of payments company Square rose 3.9% following an upgrade to outperform from market perform from Wells Fargo. The firm said Square’s underlying performance remains strong, investor sentiment is overly negative and close to inflecting, and valuation is more attractive than it has been for some time.Micron – Shares of chip stock Micron slumped 1.8% after Bloomberg News reported, citing a source, that the U.S. is unlikely to extend a temporary waiver that allows U.S. companies to sell supplies to Huawei, a Chinese telecommunications giant.Beyond Meat – Beyond Meat shares rallied 11.6% in midday trading Thursday after global fast food giant McDonald’s announced plans to try plant-based burgers in Canada. The 12-week trial will begin Sept. 30 and be marketed as the P.L.T., short for plant, lettuce and tomato. Beyond Meat is up over 500% since its initial public offering in May, when it priced at $25.Peloton – Although volatile, shares of Peloton fell 11.2% on its first day of trading on the Nasdaq. The fitness company priced its IPO at $29 per share on Wednesday and opened at $27 per share on Thursday. Peloton makes cycles and treadmills equipped with screens for users to join live and recorded fitness classes remotely.Boston Beer — Shares of Boston Beer climbed 4.3% after an analyst at BMO Capital Markets upgraded the beer maker to outperform from market perform. The analyst said the Samuel Adams beer maker could see 80% growth in 2020.Whirlpool — The home appliances maker rose 3% after an analyst at J.P. Morgan upgraded the stock to overweight from neutral, citing an “inexpensive” valuation and stabilizing steel prices.AbbVie – The biopharmaceutical company’s shares rose 2.7% after Citi upgraded the stock to buy from neutral. Citi said it expects AbbVie to “extract significant shareholder value from Allergan’s franchises,” as well as see better than expected revenue from its Skyrizi and Rinvoq lines.– CNBC’s Maggie Fitzgerald, Fred Imbert, Yun Li and Tom Franck contributed to this report.