Check out the companies making headlines before the bell. Pfizer , Moderna , BioNTech — Shares of Pfizer dropped 1.3% after the company slashed its full-year revenue guidance by $9 billion, noting waning demand for its Covid treatment and vaccine. Following the guidance cut, Jefferies upgraded Pfizer on Monday, citing an attractive buying opportunity. Vaccine markers Moderna and BioNTech also dropped premarket, losing 4.1% and 5%, respectively. Novavax shed 2.4%. Colgate-Palmolive — The consumer products stock gained more than 1% in premarket trading after Stifel upgraded Colgate-Palmolive to buy from hold. The investment firm pointed to strength in pet food line Hill’s and toothpaste as reasons to be optimistic about the stock. Varonis Systems — Shares added 4.3% after Morgan Stanley raised its price target and upgraded the security software provider, saying the growth of generative AI will help drive company growth. Manchester United — The stock dropped 8.8% on news that British billionaire Jim Ratcliffe is in talks to acquire a minority stake of Manchester United in a deal that would value the soccer club at more than $3.3 billion, according to the Wall Street Journal . Rite Aid – Shares tumbled more than 5% premarket and trading was halted after the pharmacy chain on Sunday filed for Chapter 11 bankruptcy protection in New Jersey amid slowing sales, mounting debt and lawsuits related to its alleged part in the nation’s opioid epidemic. The company said it reached a deal with creditors on a restructuring plan and appointed Jeffrey Stein as its new CEO to steer the company through it. Lululemon — Shares jumped more than 5% Monday premarket. The athleisure company will be added to the S & P 500 on Wednesday, according to S & P Dow Jones Indices. Lululemon will replace Activision Blizzard following the completion of its takeover by Microsoft. TAL Education Group — The stock climbed 3.5% following an upgrade to buy from UBS. The firm cited the stock’s attractive valuation and the rapid and profitable growth of TAL’s non-academic tutoring business as catalysts. Charles Schwab — Shares dipped slightly after the brokerage posted mixed quarterly results. The company’s earnings per share came in at 77 cents, beating an LSEG estimate of 74 cents. Revenue, however, was slightly below expectations at $4.61 billion. — CNBC’s Hakyung Kim, Jesse Pound, Tanaya Macheel, Michelle Fox Theobald and Lisa Han contributed reporting.