Check out the companies making the biggest moves in midday trading: Frontier Group — Shares of the budget airline carrier shot up more than 13% in the wake of rival Spirit Airlines' bankruptcy filing on Friday. Humana — Shares of the health insurer rose more than 2% after the company reaffirmed on Friday its fiscal 2025 earnings forecast. Humana expects to earn about $17 per share after adjustments. Following the announcement, Bank of America raised its price target, but reiterated its neutral stance on the stock United Therapeutics — The biotech soared 35% after saying its TETON-2 study evaluating the use of nebulized Tyvaso (treprostinil) Inhalation Solution to treat idiopathic pulmonary fibrosis met its primary efficacy endpoint . Ionis Pharmaceuticals — The maker of RNA-targeted medicines jumped 32% when it said Phase 3 CORE and CORE2 studies of olezarsen in patients with severe hypertriglyceridemia showed " a highly statistically significant placebo-adjusted mean reduction in fasting triglycerides of up to 72% and a highly statistically significant reduction in acute pancreatitis events of 85% with favorable safety and tolerability." PepsiCo — The snack and beverage giant rose more than 2% after activist investor Elliott Management took a $4 billion stake in the company, touting a "rare" and "historic" opportunity for a turnaround at the iconic soft drink and snack company. The investment by Elliott, founded by Paul Singer, was first reported by the Wall Street Journal . Elliott, now one of Pepsi's five largest active investors, sent a presentation and letter to Pepsi's board of directors Tuesday, detailing an agenda for restoring business momentum. Kraft Heinz — Shares tumbled nearly 7% after the food company confirmed earlier reports that it would split up into two publicly traded companies , which will be nameded at a later date. One unit, which currently goes by "Global Taste Elevation," will include Kraft's shelf-stable products such as Heinz and Kraft Mac & Cheese. The other one, "North American Grocery," will include brands such as Oscar Mayer and Lunchables. Constellation Brands — The stock tumbled 7% after the brewer cut its full-year guidance. It now expects earnings to come in between $10.77 and $11.07 per share, down from its prior guidance of $12.07 and $12.37 per share. Air Lease — Shares rose more than 6% after the aircraft leasing company reached a merger deal with Apollo, Brookfield, SMBC Aviation Capital and Sumitomo. The deal, which is expected to close in the first half of next year, values the company at about $28.2 billion including debt. Cytokinetics — The late-stage biopharmaceutical company soared 40% after it said a clinical trial of its heart disease drug, aficamten, showed a meaningful improvement in patients with symptomatic obstructive hypertrophic cardiomyopathy, than the standard of care, metoprolol. Lam Research — The stock fell 4% following a downgrade at Morgan Stanley to underweight from equal weight. The bank said it doesn't expect Lam Research to sustain growth into 2026. Biogen — The biopharma stock added almost 4% after Biogen and Eisai's said the Food and Drug Administration approved an injectable version of their Alzheimer's disease drug, Leqembi. Newmont — The gold miner gained 2% after the precious metal hit a record high of $3,508.50 earlier in Tuesday's session. —CNBC's Scott Schnipper, Michelle Fox, Fred Imbert and Alex Harring contributed reporting.
