The Dow and the S&P 500 rebounded on Thursday, boosted by financial shares and Boeing in a week so far marked by wild swings on rising angst about the spread of the new Omicron coronavirus variant globally. Boeing Co. jumped 5.7 percent after China’s aviation authority issued an airworthiness directive on the 737 MAX that will help pave the way for the jet’s return to service in China. Kroger Co. surged 12.4 percent to top the S&P 500 after the retailer raised its full-year sales and profit forecasts, boosted by sustained demand for groceries. Payments processors Visa Inc., Mastercard Inc., and American Express Co. added between 4.1 percent and 4.9 percent. All of the 11 major S&P sectors advanced, with eight of them surging more than 1 percent each. Financials led the pack, rising 3.1 percent. “Today is a relief rally in markets, but the virus and the Fed’s hawkishness—are …