Biotechnology company Abivax saw its U.S.-listed shares jump more than 500% in pre-market trading on 23 July after reporting positive maintenance-study results for its experimental ulcerative-colitis therapy obefazimod. The move followed an overnight rally of roughly 460%, turning what had been a modest holding for some investors into a double-digit share of their portfolios. The surge added more than $2 billion to Abivax’s market value and pushed the stock above $50, according to trading quotes compiled during the opening hour. Before the data release, the company’s enterprise value was estimated at around $600 million. Brokerage analysts responded by sharply lifting their price objectives. Guggenheim initiated a target of $101, Citizens JMP raised its view to $95 from $33, and Piper Sandler increased its estimate to $70 from $42. Investor models circulated after the announcement project that obefazimod could generate as much as $3 billion in peak annual sales, implying a risk-adjusted valuation near $9 billion for Abivax if the therapy succeeds in late-stage development and commercialisation.