Title of each class Trading Symbol(s) Name of each exchange on which registered Common stock: Par value $0.001 ATOM Nasdaq Capital Market Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q x Quarterly Report Pursuant to Section 13 or 15 (d) of the Securities Exchange Act of 1934 For the quarterly period ended September 30, 2019. or ¨ Transition Report Pursuant to Section 13 or 15 (d) of the Securities Exchange Act of 1934 For the transition period from ______ ...