Slashdot has reported:

Two global election markets on Polymarket’s offshore platform recorded more than $600 million in trading, much of it involving contracts on candidates who ultimately lost. Researchers identified $284 million in questionable trades connected to Ethiopia’s election and periods when 99.6 per cent of volume in a Romanian election market was flagged as suspected wash trading.

Prediction market supporters often present the platforms as measures of public opinion or “truth machines” that can offer a clearer view of events than polls and other data. In 2024, Kalshi, another prediction market, outperformed many pollsters in forecasting the outcome of the U.S. presidential race. Trading activity in the Ethiopia and Romania markets, however, raised questions about what high volumes represent.

Wash trading involves accounts repeatedly buying and selling assets to make activity appear heavier than it is, while money moves back and forth between accounts. Some accounts may also inflate their trading to qualify for possible cryptocurrency token rewards, a practice known as activity farming.

Polymarket told Wired that, in response to the Ethiopian trades, it “immediately flagged this activity, investigated, and blocked the accounts from trading.” The company did not explain why the suspicious trades were allowed to continue for months before it acted.

The figures concern two markets on Polymarket’s offshore platform, which drew far more trading than most political markets typically attract. The activity centred largely on long-shot candidates who did not win. Prediction market results can be watched as forecasts, but the reported trading patterns show that volume may also reflect manipulation or attempts to earn token rewards.