Check out the companies making headlines in midday trading. Signet Jewelers — Shares tumbled 11% after the jeweler issued first-quarter revenue guidance that missed Wall Street estimates. The company said it expects revenue in the range of between $1.47 billion and $1.53 billion, whereas analysts polled by FactSet forecast $1.61 billion. Chipotle — Shares rose 6.4% to an all-time high after the fast-casual Mexican chain announced the board approved a 50-to-1 stock split . The plan, which was shared with the public on Tuesday, is expected to go into effect in June if approved by shareholders. Deutsche Bank also raised its price target on the stock, citing strong growth prospects. Mobileye Global — The stock gained 6% after Volkswagen announced it will ramp up collaboration with the automotive tech company. Mobileye will provide new automated driving technologies to the European carmaker. FMC — Shares of the chemical manufacturer added nearly 5% after receiving an upgrade to buy from UBS. The bank thinks the stock could rally as FMC returns to meeting or beating guidance, its margins improve and the market sees an end to destocking. Riot Platforms — The bitcoin mining stock advanced 4% after JPMorgan upgraded it to overweight from neutral, citing the company’s “unique combination of industry-leading power contracts, scale and liquidity.” Best Buy — The electronics retailer got a nearly 3% lift after Telsey upgraded the stock to outperform from market perform, citing signs of stabilization and improvement due to replacement cycle and new innovative products like Ray-Ban glasses. Boeing — Shares climbed more than 2% amid a spate of reports around the beleaguered airline operator. Bloomberg, citing unnamed sources, said Boeing is exploring a possible sale of at least two of its defense businesses. Reuters, citing sources familiar, reported Boeing is exploring how Spirit AeroSystems can reduce exposure to Airbus . Carmax — The used vehicle stock rose 2% after an upgrade to buy at Needham. The investment firm said that Carmax should benefit as the used car market gets more supply and lower interest rates. General Mills — Shares moved up 1.7% after the food company posted third-quarter results that exceeded expectations on the top and bottom lines. General Mills reported adjusted earnings of $1.17 per share on revenue of $5.10 billion. Analysts polled by LSEG had expected per-share earnings of $1.05 on revenue of $4.97 billion. Equinix — Shares fell more than 4% after short seller Hindenburg Research released a report targeting the data center company. — CNBC’s Sarah Min, Alex Harring, Jesse Pound, Lisa Han and Michelle Fox contributed reporting.