U.S. stock index futures rose on Wednesday, as heavyweight Tesla gained, while hopes that the Omicron coronavirus variant is less deadly than the previous strain calmed investors amid daily cases in the country hitting a record high. The electric-car maker added 2.0 percent in premarket trading as CEO Elon Musk exercised all of his options expiring next year, signaling an end to his stock sales. Its shares are up 54 percent for the year after a 743 percent surge in 2020. Some early studies pointed to a reduced risk of hospitalization for the Omicron variant, compared with the Delta strain—an observation that has helped investors look past the travel disruptions brought about by the pandemic. U.S carriers Delta Air Lines and Alaska Air Group canceled hundreds of flights again on Tuesday as the daily U.S. infections in the United States surpassed the previous peak set in January. At 6:29 a.m. …