Here are some of the companies making headlines in midday trading. Amylyx Pharmaceuticals – Shares surged 53% after the pharmaceutical company said its avexitide treatment met its primary endpoint, as well as all secondary endpoints in a Phase 3 trial. Avexitide is a GLP-1 receptor agonist to treat post-bariatric hypoglycemia. Meta Platforms – The Facebook parent slid 3%. A key trial kicked off on Tuesday in which a group of states are suing Meta over alleged harm to children and teens . Meta's attorneys have previously said that the trial could result in damages as high as $1.4 trillion. Carvana – Shares of the online auto retailer were down more than 3% following sales of the stock from two of its directors. Late last week, director Danforth Quayle disposed of 14,525 shares of the company and director Ira Platt disposed of 30,000 shares, according to company filings delivered to the Securities and Exchange Commission on Monday. UGI Corporation – The utility popped more than 12%. The Wall Street Journal reported , citing people familiar, that KKR made a $9 billion bid to take over the utility. At one point, trading in the stock was briefly halted for volatility. Artificial intelligence stocks – Stocks linked to the AI buildout effort tanked in Tuesday's trading as investors took a risk-off posture. Photonics stocks Coherent and Lumentum tumbled about 12% and 9%, respectively. Optical networks stock Ciena lost around 10%, while Teradyne slid 9%. AI cloud computing play CoreWeave also fell 9%. Klarna – The buy-now-pay-later stock tumbled 21% on weak guidance for the third quarter and the full year. For Q3, Klarna sees revenue between $940 million and $980 million. Analysts polled by FactSet expected a forecast of $1.11 billion. The company also slashed its guidance for gross merchandise value for 2026. Baidu – The Chinese internet name dropped 12% on weaker-than-expected results for the second quarter. Earnings per average diluted share came in at 7.22 yuan, below a FactSet consensus of 9.35 per EPADS. Revenue of 31.33 billion yuan was also below an estimate of 31.78 billion. Home Depot — Shares were marginally higher after the home improvement retailer posted fiscal second-quarter results that beat expectations on the top and bottom lines , and reaffirmed its full fiscal year guidance. Adjusted earnings of $4.92 per share topped the $4.73 expected by analysts polled by LSEG. Revenue of $47.86 billion exceeded the forecast $47.27 billion. Fabrinet — The optical product manufacturer dropped more than 20%. Fabrinet said usual Q1 expense seasonality is expected to create a temporary margin headwind in fiscal Q1 2027, according to StreetAccount. Memory stocks — Memory chip makers were down as a group, with Micron Technology and SK Hynix off nearly 7% and 8%, respectively. Shares of Sandisk were also down more than 8%. Duolingo — The language learning platform rose 7% after D.A. Davidson upgraded Duolingo to buy from neutral. "While we think the market has historically priced the risks related to [daily active users] deceleration and monetization issues effectively, Duolingo is nearing a turning point," the firm said. — With reporting by CNBC's Fred Imbert, Toby Burns, Nick Wells and Darla Mercado.