Check out the companies making the biggest moves midday Monday:
Gilead Sciences — Shares of Gilead rose 3.8% after the biopharmaceutical company revealed it settled a patent case over its HIV therapies with five generic drugmakers.
Twitter — Shares of Twitter slipped 2% after the company said in a regulatory filing that Elon Musk's latest attempt to cancel the deal to buy the social media group is invalid. Most recently, Musk attempted to terminate the purchase citing Twitter's treatment of a whistleblower.
Carvana — Carvana surged 7.8% after it was upgraded to overweight from neutral by Piper Sandler. Analyst Alexander Potter called the stock "grossly undervalued" and believes Carvana could double from current levels.
Newmont — The gold mining company gained 2.6% after Goldman Sachs initiated coverage of the stock with a buy rating. Analyst Emily Chieng said Newmont looks undervalued after falling 30% and pointed to the company's new development projects in the pipeline that can boost growth.
Amgen — Amgen shares fell 3.7% after the approval of Bristol-Myer Squibb's psoriasis drug, which will compete with Amgen's Otezla. Separately, the biotech company reported over the weekend that its Lumakras pill reduced the risk of lung cancer progression by 34% compared with chemotherapy in a clinical trial.
Alphatec — Shares jumped 7.7% after Morgan Stanley initiated coverage of the medical technology company with an overweight rating. According to the firm, Alphatec outpaces peers and has "significant runway" head for double-digit revenue growth in the spine surgery space.
Energy stocks — Rising oil prices helped push energy stocks higher. APA was the biggest winner of the day, jumping more than 5% after Citi upgraded the oil and gas company to buy from neutral. Hess and Marathon Oil were both up more than 3%, while Devon Energy rose nearly 4%. Exxon Mobil was up more than 1%.
Truckers and logistics companies — Transportation services company Yellow jumped nearly 6%, while trucking company Heartland Express rose more than 3%, and Old Dominion Freight Line and Saia saw almost 3% gains. The moves come as concerns about a possible railroad strike heat up.
— CNBC's Sam Subin, Carmen Reinicke and Sarah Min contributed to this report.