Let's say I'm an actor with a non-obvious insight into the future effects of Fed policy.
How does Truthcoin incentivize me to add my insight to the market? My status as someone with non-obvious insight into the future effects of Fed policy means my opportunity cost is rather high.
Not speaking for TruthCoin here but any prediction market, especially one that can be used anonymously, should incentivize you to bet on your insight in the hope of making money. When you bet this will move the price (at least somewhat) which will make that price a better indicator of Fed policy or whatever than it would have been without your participation.