Check out the companies making headlines in midday trading. Southwest Airlines — The stock rose 9% after activist hedge fund Elliott Management amassed a $1.9 billion stake in Southwest Airlines. The firm it seeks to replace Southwest CEO Bob Jordan and Chairman Gary Kelly. GameStop — The meme stock slipped nearly 15% in volatile trading after a roller-coaster week. GameStop added to Friday’s steep losses after investors responded to the company’s earlier announcement that sales dropped significantly in the first quarter and that it was selling more stock. Meme stock leader Keith Gill hosted his first livestream in a few years on Friday discussing GameStop, but he offered no new reasoning for his bullish thesis and his large stake. Huntington Bancshares — The bank slid more than 5% after updating its guidance for the full year. Huntington is now calling for net interest income to decline by 1% to 4%. Previously, it called for a range reflecting a decline of 2% to a gain of 2%. In a presentation , Huntington said to “expect sequential increases from 1Q24 level, accelerating into 2H24 and 2025.” Advanced Micro Devices — The chipmaker fell 3% after Morgan Stanley downgraded shares to equal weight from overweight, saying that investors’ expectations look elevated. KKR , CrowdStrike , GoDaddy — KKR, CrowdStrike and GoDaddy shares all rose after the announcement that the three companies will join the S & P 500. The stocks rose 11%, 9% and 2%, respectively. The S & P Dow Jones Indices announced Friday that the companies are set to join the index on June 24 as part of its quarterly rebalance, with Robert Half , Comerica and Illumina all leaving the index. While shares of Robert Half were nearly 1% higher, Comerica and Illumina fell 1.5% and 4.5%, respectively. Apple — Shares slipped 0.4% ahead of the iPhone maker’s Worldwide Developers Conference on Monday. The company is widely expected to unveil new artificial intelligence-related features . ReNew Energy Global — Shares popped more than 7% after Morgan Stanley upped its price target, saying the narrative for the U.K.-based company remains strong. The firm said ReNew is strongly positioned to play India’s energy transition. Planet Fitness — The gym chain advanced 4% on the back of a Jefferies upgrade to buy from hold. The bank said the stock can rally following recent weakness as a new chief executive takes the wheel. Price increases and adjustments to the franchisee model can also help shares, Jefferies said. DraftKings — The sports entertainment stock gained 2% after Morgan Stanley re-named the company as a top pick. The firm said that Illinois’ recent legalization of a progressive tax on sports-betting companies has led to overdone concerns on the stock, which has seen a tough quarter. — Tech Zone Daily’s Yun Li, Alex Harring, Michelle Fox, Sarah Min, Pia Singh and Sean Conlon contributed reporting.