Check out the companies making headlines in midday trading. China stocks – U.S.-listed shares of Chinese companies fell after Beijing’s economic planning agency failed to announce any new major stimulus plans . Online video company Bilibili fell 13%, while automaker Nio and Temu parent PDD tumbled about 6% each. E-commerce companies JD.com and Alibaba both declined roughly 7%. Las Vegas Sands , Wynn Resorts – The casino operators, which both have ties to China through their resorts in Macau, fell more than 2% and 1%, respectively, after the country didn’t unveil any new stimulus measures . DocuSign – The electronic signatures company rose 8% following the announcement that it is set to replace MDU Resources in the S & P MidCap 400 index on Friday. Super Micro Computer — Shares of the computer server company pulled back more than 5%. Super Micro surged a day earlier after the firm said it issued more than 100,000 graphics processing units to “some of the largest AI factories ever built.” Nvidia — The artificial intelligence darling climbed more than 3%. Foxconn chairman Young Liu told CNBC that the artificial intelligence boom “still has some time to go.” He added that demand for Foxconn servers based on Nvidia’s forthcoming key AI Blackwell chip is “much better than we thought.” Humana — Shares jumped 2.8% after Bernstein upgraded the beaten-down health insurance company to outperform, even though it substantially decreased its price target. The firm views risks to the stock as being incorporated into expectations and thinks Humana is now an “attractive investment.” Roblox — Shares fell 4% after Hindenburg Research disclosed a short position on the gaming platform, alleging the company inflated metrics. Roblox rejected the claims, calling them “misleading.” Sphere Entertainment — The live entertainment and media company pulled back 7% afte r Sphere announced that chief financial officer David Byrnes will leave the company . The firm said that Byrnes will stay in his current role for an interim period to aid the transition. Waters Corp — Shares of the lab equipment provider added 2.7% on the back of a Jefferies upgrade to buy from hold. Jefferies said there’s a super cycle for product replacement underway. Affirm — The buy now, pay later company advanced more than 6%. BTIG upgraded Affirm to buy , with analyst Vincent Caintic lauding the company’s growth compared to traditional payment companies like American Express. — CNBC’s Michelle Fox, Hakyung Kim, Pia Singh, Sean Conlon and Alex Harring contributed reporting