Opinion: If a single trader can manipulate the outcome of a prediction market, that market should not be listed for trading

Odaily News As prediction market platforms like Polymarket gain mainstream attention during the US election cycle and geopolitical events, their prices are increasingly cited as real-time signals. However, this premise fails when contracts create economic incentives for participants to change the very outcomes they are meant to measure.

The core issue lies in product design, not volatility. When a single outcome can be achieved by a single actor through a single action, the contract transforms from a prediction tool into an execution script. The article cites the example of betting on a field invasion during the Super Bowl, pointing out that traders who bet "Yes" have personally carried out the action, a scenario that has already occurred in reality.

Political and event-based markets are particularly vulnerable, as they often rely on discrete nodes that can be influenced at low cost and have relatively thin liquidity. If participants begin to suspect that outcomes are being artificially manufactured, the platform loses credibility. The article argues that sports markets, due to their high visibility, multi-layered governance, and multi-party participation structure, are harder to manipulate at an individual level and should serve as a structural reference point.

Prediction market platforms should establish clear listing standards, excluding contracts that can be manipulated by a single participant at low cost or that constitute a bounty for harm. Otherwise, external regulation will intervene.