This may be the purpose of a prediction market for an outside observer. But the outside observer and the US government (or any org that holds private informatio

This may be the purpose of a prediction market for an outside observer. But the outside observer and the US government (or any org that holds private information) have different purposes - it's an adversarial mechanism. In particular: the government is free to just publish any insider/true information that it wants the public to know about. If it shared that purpose then the market wouldn't need to exist.