Gilead Sciences is trading at ARS 61,975, up 4.16%, with its newly disclosed collaboration with Vir Biotechnology the most likely catalyst cited in coverage. - The companies plan to develop three solid-tumor T-cell engager candidates; terms include $90 million upfront and potential milestones. - The gain contrasts with a 2.01% biotech-sector decline and falling major U.S. indexes. - No trading-volume data was available, and the collaboration is a likely explanation, not confirmed causation.