We study trading gains and losses on Polymarket, the largest prediction market. Using 588 million trades ($67 billion in volume), we show that the gains are highly concentrated: the top 1% of users capture 76.5% of profits. Successful traders provide liquidity using limit orders that resolve favorably relative to realized outcomes while unsuccessful traders take liquidity using market orders. Monthly performance is weakly persistent, however, this may represent sample selection rather than skill. A detailed analysis of the trading behavior of the most successful accounts suggests that "insider'' trading is unlikely to explain the performance of the largest winners.

Full dataset available at https://huggingface.co/datasets/vgregoire/polymarket-users

insider trading on events probably wouldn't show any trends, right? These are point in time events (they call them markets), but they are finite and short lived. An insider would be a one and done thing, so it would be pretty hard to spot them or trend any sort of month over month insider scheming imo.

Also...

> We study trading gains and losses on Polymarket, the largest prediction market

This is not a natural thing to say and I fucking hate that it's impossible to know anymore if I'm wasting time replying to an AI/bot or not

Not meant to sound like AI, but most academic journals limit abstracts to 100 words, so they rarely feel natural...

I agree: insiders are hard to study because they are finite and short-lived. We're pretty confident there are insiders out there trading on Polymarket; however, our conclusion is that they don't account for a significant fraction of the total trading gains on the platform.

I agree - you're not going to be an insider on a significant proportion of trades and it would be stupid to use the same account for more than a couple.

Insiders are going to be earning large amounts in single trades, either by betting a lot when it's odds-on or a small amount when it's out the odds (for a large return).

I think it's just bad tense, which I think makes it not AI amusingly.