Computing

Polymarket Saw $600 Million in Post-Election Trades

Millions of dollars continued changing hands on Polymarket long after election outcomes were effectively decided, raising questions among prediction market experts.

Radwan AbdulhadiEditor and technology writer

Published: October 17, 2026 · Updated: October 17, 2026 · 5 min read

Polymarket Saw $600 Million in Post-Election Trades — Image: Ars Technica

Post-Election Trading Surges

Prediction market boosters often tout platforms as barometers of public opinion or truth machines offering clearer pictures of where things are headed than polling data. While platforms like Kalshi beat many pollsters in forecasting the 2024 US presidential race, prediction market trading activity can also reveal more perplexing stories.

Two global election markets hosted on Polymarket's offshore platform generated over $600 million in trading volume, far eclipsing what most political markets typically attract. Most of this heavy trading activity took place through buying and selling contracts tied to long-shot candidates who ultimately did not win their respective races.

The Ethiopian Election Zombie Market

Earlier this year, Ethiopian Prime Minister Abiy Ahmed's Prosperity Party cruised to victory in federal elections, securing 438 parliamentary seats and paving the way for another five-year term while the closest competitor won only 13 seats. Typically, prediction market volume tracks roughly with the odds of a given outcome, meaning frontrunners attract far more volume than long shots.

However, trading patterns for the Ethiopian election deviated sharply from the norm. Just $173,000 was wagered on Ahmed winning, compared to more than $41 million traded on his chief of staff, Shimelis Abdisa, becoming the country's next leader. Altogether, the volume traded added up to over $285 million, with nearly all of it concentrated on losing candidates.

According to former Polymarket trader Chris Park, who runs the prediction-market forensic analysis firm MSR Decode, nearly all of that volume—about $284 million—came from pairs of accounts repeatedly buying and selling with each other. This high volume of back-and-forth transactions prompted Barnard College economics professor Rajiv Sethi to describe the behavior as an obvious form of volume manipulation.

Zombies and Suspicious Romanian Markets

The timing of these trades added further confusion. Polymarket's rules dictated that the Ethiopia market would be resolved in October after the prime minister was formally appointed and sworn in, keeping the market open for months after Ahmed's victory was a foregone conclusion. For 123 days following the election, bursts of irrational trading continued, leading users to leave frustrated comments.

Rajiv Sethi characterizes this phenomenon as a "zombie market," where users continue buying and trading on events that have already concluded. An even more dramatic trading anomaly was observed in a market covering a 2024 election in Romania, where the initial vote was called off due to fears regarding foreign interference.

Although a new race was held several months later, Polymarket kept the original market running alongside the new option. An algorithm developed by Sethi and his colleagues to flag potential wash trading identified nearly all the volume in that older market as suspicious, with certain weeks showing 99.6 percent of volume flagged as wash trading.

Over $600 Million in Polymarket Election Trades Took Place After Races Ended — Image related to the report from WIRED · Source: WIRED

Investigation and Token Farming Hypotheses

Wash trading involves accounts repeatedly buying and selling assets to create an illusion of heavy activity while money simply moves back and forth. The practice is banned on regulated US financial exchanges and is specifically prohibited under Polymarket's terms of service.

An earlier study conducted by Sethi and his colleagues previously found widespread evidence of wash trading on Polymarket's platform. When asked about the recent election markets, Shana Bautista, Polymarket's head of global intelligence and investigations, stated that the team immediately flagged the activity, investigated, and blocked the accounts from trading. However, Polymarket did not respond to follow-up questions regarding how those accounts were able to amass such high volume before action was taken.

MSR Decode's analysis of the Ethiopian market pointed toward "activity farming" as the most likely driver, where traders artificially inflate volume to benefit from a potential cryptocurrency token launch. In 2025, Polymarket chief marketing officer Matthew Modabber mentioned that there would be a token, though specific details were omitted.

Andre Guettler, director of Ulm University's Institute of Strategic Management and Finance, noted that such behaviors are textbook examples of market participants farming potential airdrops. MSR Decode analyzed over 38,000 trade loops following the Ethiopian election and found that over 98 percent resulted in neither profit nor loss, with a median contract holding time of just nine seconds.

Broader Scrutiny on Prediction Markets

Unusual trading patterns are not entirely new to prediction platforms. Earlier reports highlighted how markets predicting the 2028 US presidential election heavily featured unlikely candidates such as Elon Musk and New York City Mayor Zohran Mamdani, neither of whom meets constitutional eligibility requirements.

Both Polymarket and its rival Kalshi have faced public scrutiny for unusual market activities in recent months. Kalshi recently confronted intense public furor on social media regarding suspicious trading volume on its cryptocurrency perpetual futures market, prompting the company to publish a blog post denying allegations of wash trading.

Sources

Ars TechnicaPolymarket saw $600 million in election trades after the elections were over
WIREDOver $600 Million in Polymarket Election Trades Took Place After Races Ended