We don't cover FBRX, and we'd rather say so than guess.
Forte Biosciences, Inc. (FBRX) is a $1.6B-cap name with thin filing history and little wire coverage. There isn't enough source material to explain a move honestly — and an explanation we can't source is worse than none.
Small caps with no filings and no coverage produce bad explanations. Drawing the line publicly is the point — it's how you know every other answer here means something.