The price wasn't wrong — the question was wrong. By the day of the race, every reasonable horse-by-horse comparison had already been priced. What the market couldn't price was that one runner had broken the assumption underneath the math: the assumption that thoroughbreds get tired in a specific shape over a mile and a half. He didn't. The chart had nothing left to model.
Modern markets do this constantly. Every closing line is a portrait of consensus. When the result blows past the closing line, the lesson is rarely about the winner. It's about the assumption that anchored everyone else's number — the unspoken floor or ceiling that the entire price ladder was sitting on. Find that floor and you find the next mispriced number.