alt Hacker News> In prediction markets if the markets are fully efficiently priced, in the absence of transaction costs you WILL get 100% back in the long run.
This is basically equivalent to the observation that, in a perfectly efficient market, no entity can ever make a profit.
And yet, in the real world, entities make profits all the time. In fact, they make wild, unimaginable, world-changing, history-altering profits. This is a tacit admission that our markets aren't even remotely efficient, and that includes predictions markets. Efficient, rational markets are the exception, not the rule.
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Free markets aren't even an exception. They're an abstract construction that exists to make economic analysis scientific by removing all confounding variables from the equation. I'd be extremely surprised to find one example where the conditions required of a free market truly existed.
If people knew more about economics than just whatever is being parroted as 'economics' in mainstream media they would know that there's a variety of types of markets that happen in the real world and none of them are the abstraction of a free market that allows econ 201 students to compare what happens when you introduce trade between a country that produces 4 apples for 3$ each and a country that produces 5 oranges for 4$ each.
You misunderstood a basic principle here.
In a perfectly efficient market all entries can make the same profit on a given investment at the same level of risk and time horizon. There’s nothing inefficient about a market having a risk premium etc.