BEIJING—Global stocks and Wall Street futures were mixed Thursday as traders tried to figure out the potential impact of the latest coronavirus variant. London and Frankfurt opened lower and Shanghai and Tokyo fell. Hong Kong advanced. It is unclear whether omicron is more dangerous than other variants. But governments have responded by tightening travel controls. That is fueling unease about the outlook for a global economic recovery. On Wall Street, the future for the Dow Jones Industrial Average was up 0.6 percent and that for the S&P 500 index gained 0.5 percent. The sank 1.2 percent on Wednesday despite surveys showing hiring and factory activity in November were better than expected. Markets already were sliding when the White House announced the discovery of the first omicron case in the United States. On Wednesday, the Dow declined 1.3 percent and the Nasdaq slid 1.8 percent. In early trading Thursday, the FTSE …