 Shares of Chembio Diagnostics Inc. skyrocketed 63.8 on record volume in afternoon trading Monday, to pace all gainers listed on major U.S. exchanges, in the wake of the point-of-care diagnostics companys announcement of the commercial launch of its rapid COVID-19flu test. The stock was on track for the biggest one-day percentage gain since it doubled, on March 12, 2004. 