Marker Therapeutics is trading 16.64% lower in pre-market at $1.00 on October 20, 2026, amid biotech-sector weakness; no clear company-specific negative catalyst was identified. - Supplied sector data shows XBI down 3.65%, though it does not establish the cause of the full stock decline. - On October 19, the company announced a positive $2.6 million FDA grant to fund a Phase 1 MT-601 pancreatic cancer study, planned to begin in Q1 2027; that news does not explain the decline.