Whale Manipulates Polymarket Prediction Markets

The prediction market on the Polymarket platform reached an erroneous resolution due to oracle manipulation. This was reported by journalist Colin Wu, citing a statement from the team on Discord.

A governance attack occurred on Polymarket, where a UMA tycoon used his voting power to manipulate the oracle, allowing the market to settle false results and successfully profit. The tycoon cast 5 million tokens through three accounts, accounting for 25% of the total votes.… pic.twitter.com/3xFuzdRfWJ

— Wu Blockchain (@WuBlockchain) March 26, 2025

The issue concerns bets amounting to approximately $7 million on the outcome of ongoing negotiations between Ukraine and the USA regarding a rare earth metals deal.

It is reported that a UMA whale contributed 5 million tokens through three accounts in the oracle-side voting, leading to an erroneous and premature resolution. This major participant accounted for 25% of all votes.

According to one commentator on Polymarket, some other prediction markets faced similar issues allegedly due to manipulation by UMA.

Users were outraged by the possibility of whales influencing oracle data and the outcomes of prediction markets.

“UMA must go or this site will die. With the precedent this situation creates, anything can be resolved at the whim of whales,” noted one commentator.

The team promised to make efforts to prevent similar incidents.

Back in March, an expert assessed Polymarket’s prediction accuracy at 94%.