BEIJING—Global stock markets were mixed Thursday after Wall Street hit a high and new daily U.S. coronavirus cases surged to a record. London and Frankfurt opened lower and Tokyo and Seoul also declined. Shanghai and Hong Kong advanced. Wall Street futures were higher after the benchmark S&P 500 index on Wednesday hit its 70th record high of 2021. Optimism was tempered by data showing new U.S. virus cases have risen to an average of 265,000 per day, driven largely by the more contagious omicron variant. Markets are “hanging onto thin optimism” while health care resources do a “balancing act,” Tan Boon Heng of Mizuho Bank said in a report. In early trading, the FTSE 100 in London lost 0.1 percent to 7,411.22 and Frankfurt’s DAX shed less than 0.1 percent to 15,844.18. The CAC 40 in Paris advanced less than 0.1 percent to 7,163.96. On Wall Street, the futures for …