About $200 million in Polymarket trades were flagged as potentially involving insider activity during the first half of 2026.
Polymarket, a prediction market exchange, saw roughly $200 million worth of trades flagged for possible insider activity, Bloomberg found after analyzing about 34,000 transactions identified by Polysights, a prediction market analytics platform.
The system considers factors such as how recently a wallet was created, the size and timing of a bet, the odds when the trader entered the market and whether the account concentrates nearly all its activity in one or a handful of markets.
Still, the flags don’t prove wrongdoing, Bloomberg noted, since some traders may simply have better research, sharper instincts or good luck.
Read also: Polymarket Faces Czech Block Over Unlicensed Gambling
“They’re Getting More Sophisticated”
Even so, the patterns became harder to ignore after the start of 2026. Flagged trading peaked in February as users placed large bets tied to U.S. military action and the war involving Iran.
Profits were also heavily concentrated. The top 1% of profitable wallets captured more than half of the winnings, while 57% of those wallets had been created less than 24 hours before their suspicious trades, the data shows.
- For instance, one fresh account reportedly made $370,000 betting on a permanent U.S.-Iran peace agreement at odds as low as 6%, just two hours after the wallet was created.
- In another case, 38 connected wallets placed bets across 90 markets tied to Iran and Venezuela, won 98% of them and made about $1.6 million. All later withdrew through the same Coinbase deposit account.
Tre Upshaw, the creator of Polysights, told Bloomberg that insiders are getting “more sophisticated about how they enter markets and how they accumulate trades.”
Polymarket told Bloomberg it monitors insider trading and other illegal activity and has referred nearly 100 wallets to law enforcement.
Polymarket’s key rival Kalshi said its enforcement team opened more than 150 investigations in Q1, blocked more than 100 potential insider trades with new screening tools and made more than 20 referrals to law enforcement, Bitcoin Foundation reported earlier.
Read more: Study: Five-Minute Polymarket Bitcoin Prediction Markets Enable Price Manipulation
