- Recent investigations indicate that Polymarket trades are double-counted on most public dashboards.
- The issue stems from redundant maker and taker events in the smart contracts.
- According to the allegations, actual volumes may be roughly half of what dashboards report.
Polymarket, a leading prediction market platform, has come under scrutiny after research by Storm Slivkoff suggested that the platform’s reported trading volumes may be systematically inflated on many public analytics dashboards.
The controversy has drawn attention from industry experts, data analysts, and market participants, raising questions about how trading activity on decentralized prediction markets is measured and reported.
Polymarket emits separate OrderFilled events for maker and taker
Storm Slivkoff, a partner at Paradigm, identified a technical discrepancy in Polymarket’s on-chain smart contract data. His findings, later highlighted by Paradigm co-founder Matt Huang, show that the platform emits distinct OrderFilled events for both the maker and the taker side of each trade.
While each event is technically correct, most public dashboards aggregate all events indiscriminately and end up counting the same trade twice.
found a pretty major data bug
it turns out almost every major dashboard has been double-counting Polymarket volume (not related to wash trading)
this is because Polymarket’s onchain data contains redundant representations of each trade. receipts ⬇️⬇️ pic.twitter.com/rQJEzs2Rfl
— storm (@notnotstorm) December 8, 2025
A single transaction illustrates the problem: a trade for YES tokens worth $4.13 generated two identical events for the same amount, which dashboards then summed to report $8.26 in trading volume.
Slivkoff noted that the bug affects both nominal volume (the number of contracts traded) and cashflow volume (the dollar value exchanged), thereby inflating the reported size of each trade.
Importantly, the issue is unrelated to wash trading and instead results from the way Polymarket’s contracts output event data.
Polymarket disputes the double-counting claims
Polymarket’s internal team responded swiftly, asserting that the official platform reports user-facing volume without double-counting and follows common industry practices.
The company emphasized that the problem primarily impacts third-party dashboards that consume raw contract events without implementing corrections for redundant entries.
Several major data providers, including DefiLlama, Allium Labs, and Blockworks, confirmed they are updating their dashboards to account for the discrepancy.
However, some data providers defended their existing methods, saying that more sophisticated dashboards have accounted for this distinction since 2024, even if their approaches were not formally documented.
Others criticized Paradigm for potential bias, noting the firm’s investment in Kalshi, a competing U.S.-based prediction market.
Broader market implications
Beyond the immediate issue of reported volume, the episode highlights larger challenges in accurately measuring activity on prediction market platforms.
Low-priced contracts can generate nominal volumes that look large relative to the actual capital at risk, making traditional volume metrics potentially misleading.
Experts have suggested that alternative indicators—such as open interest and fee revenue—may provide a clearer picture of platform activity.
The timing of the revelation is notable: it coincides with Polymarket’s plans for a full U.S. relaunch following CFTC approval and reports of a potential valuation in the $12–15 billion range.
The platform is also exploring an internal market-making operation that could trade against customers, prompting additional scrutiny and comparisons with competitors like Kalshi.