One in Three Moves Is Fake

The finding Prediction markets are supposed to price a headline once and hold it. The news breaks, traders read it, the price adjusts, and the new price stands. If that were the whole story, the first move after a headline would be the move, and holding it would be the default. It is not the default. We took every reaction of two cents or more that we measured on Polymarket between April 29 and June 25, 2026, more than 60,000 in all, and sorted each one by the shape it traced over the four hours after its headline. They fall into just five recurring trajectories. The clean move that ramps and sticks, the shape most people assume every reaction has, is barely one in three. The other four do something the folk model does not allow: they grind up late, blow clean past their first peak, fade back toward nothing, or turn and cross to the other side of where they began. In prediction markets, the shape of the move is the message. The One in Three Moves Is Fake study · Vera Research Three shapes that stick Three of the five hold or extend the move. Snap-and-hold (29.1%) ramps toward its peak inside the first hour and keeps it. Slow-grind (25.3%) barely moves early, then reprices late. Acc...