Another slightly more complicated version of this could exist where there would be something to lose, this one would require the votes not be in the poll option however but on comments.
This version would require outcomes to be determined before comments pay out (within 7 days), thus long-term predictions like "when will Trump nuke the planet?" may not be feasible for it. This version would simply have a larger stakeholder(s) use their downvote mana to downvote the wrong predictions. Thus, those who bet their vote on the wrong outcomes would not receive curation rewards.
There is a version of this when downvoting, now I know. So it's sad that others don't get anything. Yeah, I agree that you also need to wait seven days before paying out rewards in the comments.
This version sounds more fun as it's hard to manipulate.
But then, we socifi.... Trying something new is always risky.