Polymarket Volume Inflated by ‘Artificial’ Activity, Study Finds

The volume of activity on Polymarket, one of the most popular prediction markets, has been significantly inflated by so-called wash trading in which users rapidly buy and sell the same contracts, according to a new study by Columbia University researchers.

The “artificial trading,” as the authors call it, varied over time but accounted for an average of 25% of all buying and selling on Polymarket over the past three years, the researchers concluded.

The paper, which has not undergone peer review, was posted Thursday on the open-access research platform SSRN. A representative for Polymarket said the company didn’t have an ...