Check out the companies making headlines in midday trading.

Blackberry — Shares of the tech company were down 4% in midday trading after surging more than 20% shortly after the opening bell. Blackberry has become one of the most-discussed stocks on Reddit in recent days, which helped to fuel a rally.

GameStop, Bed Bath & Beyond and Express — Other meme stocks popular among retail investors dropped Thursday mirroring AMC’s fall. Shares of GameStop, which made headlines earlier this year in a short squeeze fueled by retail traders, erased 10%. Bed Bath & Beyond shares fell 25% after rallying more than 60% the day prior. Shares of Express tumbled 23% after the retailer announced a stock sale plan of 15 million shares.

General Motors — Shares of General Motors jumped 5% after the auto maker said it would ramp up production of large- and mid-sized pickups in North America to meet rising demand. The company also raised its expectations for financial results from the first half of 2021.

FireEye – Shares of the cybersecurity firm dropped 14% after the company said it’s selling its products business to Symphony Technology Group – a private equity firm – for $1.2 billion. The sale includes the “FireEye” name. The remaining cyber forensics unit will be known as Mandiant Solutions. “After closing, we will be able to concentrate exclusively on scaling our intelligence and frontline expertise through the Mandiant Advantage platform, while the FireEye Products business will be able to prioritize investment on its cloud-first security product portfolio,” CEO Kevin Mandia said. 

Splunk — Shares of the software company tanked more than 8% in midday trading after reporting a wider-than-expected quarterly loss. Splunk lost 91 cents per share, more than the expected 70 cents per share, according to Refinitiv. Revenue, however, topped analyst estimates.

— CNBC’s Maggie Fitzgerald, Tanaya Macheel, Yun Li, Tom Franck, Jesse Pound and Pippa Stevens contributed reporting