Polymarket is investigating a string of well-timed and profitable trades on the Israeli election this week in the latest case to raise concerns about potential insider trading on prediction markets.

Just before the polls closed on Tuesday, hundreds of new accounts placed bets that Benjamin Netanyahu and his Likud party would do better than opponents, according to a Bloomberg analysis of Polymarket’s blockchain ledger. Those trades quickly became profitable — and together some of the accounts already cashed out over $100,000 — after some exit polls showed that Netanyahu’s party had won more seats than early reports suggested.

Polymarket is reviewing dozens of newly created wallets that traded on the election, the company’s internal investigative team told Bloomberg.

Two data analysis firms that have identified previous prediction market insider trading cases, Polysights and Bubblemaps, told Bloomberg that they have also flagged the trades as suspicious and are looking into the activity. The bets are visible because every transaction on Polymarket’s international cryptocurrency-based exchange is logged on a public ledger using blockchain technology.

The initial analysis is far from conclusive and it can be hard to separate insider trading from original research or lucky trades, especially in markets with millions of trades happening each minute.

Polymarket traders had consistently given opposition leader Gadi Eisenkot a higher chance of becoming the next leader since mid-July, reflecting polling that showed flagging support for Netanyahu. But after the polls closed on Tuesday, Netanyahu’s odds on Polymarket quickly soared to 54% while Eisenkot’s dropped sharply to 23%.

The investigative teams are looking at trading on two markets, one focused on whether Netanyahu will be the next prime minister and another on whether Likud would get the most seats of any party. Many wallets have significant gains that have not yet been realized.

The election bets are the latest in a string of well-timed prediction-market wagers around sensitive political events. Israeli authorities filed charges earlier this year against a military reservist and a civilian for allegedly using secret military information to place wagers on Polymarket related to the country’s security operations in Iran.

In the US, federal prosecutors brought charges against soldier Gannon Ken Van Dyke, alleging that he had used highly sensitive information about a military operation in Venezuela to reap more than $400,000 in profit on Polymarket.

An initial Bloomberg News analysis identified more than 600 wallets that were created on the same day, with no prior trading history, that bet on either Netanyahu winning the election or the Likud party coming out on top.