CrowdIntelDefinition
What is Longshot bias?
The tendency for cheap, unlikely outcomes to be systematically overpriced and heavy favorites underpriced — a persistent inefficiency in betting and prediction markets.
In detail
Longshot bias is a well-documented pattern where bettors overpay for low-probability 'longshot' outcomes and underpay for likely favorites. A contract priced at 3¢ may win far less than 3% of the time, while a 90¢ favorite may win more than 90%. The bias comes from the appeal of large payouts and from small-stake noise. On Polymarket it shows up in the tails: sub-cent longshots are chronically overbought, and steep favorites are often mildly cheap. Knowing the bias lets sharp traders fade longshots and back underpriced favorites.
How CrowdIntel measures it
CrowdIntel's calibration analysis bins every resolved market by entry price and compares implied probability to realized frequency across the full trade history. That surfaces where the market is mispriced — for example sub-1¢ longshots winning a fraction of their implied rate — and flags wallets whose edge comes from systematically exploiting the bias rather than from private information.
Frequently asked
What is longshot bias in prediction markets?
Cheap unlikely outcomes are overpriced and heavy favorites underpriced. Bettors overpay for the chance at a big payout, which leaves favorites slightly cheap.
Does Polymarket have longshot bias?
Yes, most visibly in the tails: sub-cent longshots win less than their price implies, and steep favorites are often mildly underpriced. CrowdIntel's calibration curve quantifies it.
How do traders exploit longshot bias?
By fading overpriced longshots and backing underpriced favorites over many markets — a small, repeatable edge rather than a single big win.
Related terms
- Market calibration
How closely a market's prices match real-world frequencies — a market is well-calibrated if outcomes priced at 70% happen about 70% of the time.
- Prediction market
A market where participants trade contracts whose payout depends on the outcome of a future event — producing prices that aggregate crowd beliefs into probability estimates.
- Smart money (Polymarket)
Wallets with proven track records of winning more than random chance — used as a leading indicator of where prices will move on Polymarket.
- Scope edge
The gap between a wallet's win rate inside a narrow scope (one topic, one category, one market) and its global win rate — a signal that the wallet has information advantage in that specific scope.