** Shares of clinical-stage oncology company Boundless Bio BOLD.O rallied ~72% to $2.4 in premarket trading

** Co and biotechnology firm Serapha Bio to merge in an all-stock deal

** Co's stockholders expected to own ~3.7% and Serapha stockholders expected to own ~96.3% of the combined co

** Combined entity will be named Serapha Bio, Inc. and is expected to list on Nasdaq under ticker "AATD"

** Prior to closing, co expects to declare a cash dividend to pre-merger stockholders to distribute excess net cash

** Serapha raises $230 million in private funding in support of the merger, co-led by RA Capital Management and RTW Investments, as well as backing from Janus Henderson Investors

** YTD, BOLD has risen ~17%