HP logo, at Hewlett-Packard pavilion, during theMobile World Congress day 3, on February 28, 2018 in Barcelona, Spain. (Photo by Joan Cros/NurPhoto via Getty Images)NurPhoto | NurPhoto | Getty ImagesCheck out the companies making headlines in midday trading:Blackstone – Shares of the alternative asset manager shed 0.2% following a downgrade to neutral at Bank of America. The firm said that while Blackstone is “very well-positioned over the long term” they see “more modest upside” ahead after the stock’s 55% surge this year.Hewlett Packard Enterprise — HP shares rose 4.1% after an analyst at Evercore ISI upgraded them to in-line from underperform. The analyst said HPE now has a better “risk/reward dynamic,” citing solid cash flow, an attractive valuation and the acquisition of supercomputer builder Cray.AMC – Shares of the entertainment company lost 2.4% after Evercore downgraded the stock to underperform. The firm said that “accelerating cord-cutting trends” makes the stock “unfavorable at current levels.”Western Digital – Shares of the computer hard-disk maker rose 1.6% after an analyst at Loop Capital upgraded Western Digital to buy from hold, noting the company can deliver earnings and revenue upside for the final two quarters of 2019.Tapestry – Shares of the luxury lifestyle brands company dropped 2.8% after UBS lowered its rating on the stock to neutral from buy. UBS believes Tapestry will continue to face both widespread and industry headwinds, limiting its upside.General Motors – GM’s stock slipped 0.2% after the United Auto Workers (UAW) union announced it was countering the automaker’s latest offer. The UAW strike has lasted nearly a month, disputing GM production as multiple key manufacturing locations.Beyond Meat – Shares of the plant-based burger maker slid 3.9% after Wells Fargo initiated coverage on the stock with a market perform rating. The firm said “competition is poised to intensify” and that there’s “limited visibility into restaurant and foodservice success.”CrowdStrike – Shares of cybersecurity technology company CrowdStrike tanked 9.5% after Citi initiated coverage of the stock with a sell rating. The firm said CrowdStrike won’t be able to sustain its current growth level and is trading above normal software multiples.Planet Fitness – Shares of Planet Fitness rose 3.7% following an upgrade from Imperial to outperform from in-line. The firm said Planet Fitness is a “best in class” fitness operator with good management. Imperial called the stock a “core long-term holding.”SmileDirectClub – The teeth-straightening startup’s stock tanked 12.9% after California Governor Gavin Newsom signed a bill that is expected to how the company’s “teledentistry” service is regulated. SmileDirectClub shares have lost more than half their value since the company’s IPO on Sept. 12.– CNBC’s Maggie Fitzgerald, Pippa Stevens and Fred Imbert contributed to this report.