UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $0.001 par value per share CATB The Nasdaq Stock Market LLC FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to ...