Burning Rock Biotech Ltd.’s share price flared up on Tuesday morning on news of U.S. FDA breakthrough device designation for its Overc multi-cancer detection blood test (MCDBT). The stock closed on Dec. 30, 2022, at $2.26 and rose sharply on the announcement to open at $2.89. By the end of the day, however, the stock had sunk to $2.15.