A recent study by Guangzhe Wang indicates that a distinctive pattern of Binance trading activity around the settlement of Polymarket's five-minute Bitcoin contracts has subsided following an August reform that changed how the contracts are settled. The finding offers an empirical test of the reform's effect, though it does not address whether manipulation has been eliminated or how much traders may lose under the current rule.
Background: From Snapshots to Averages
Polymarket's five-minute Bitcoin contracts previously settled based on a single snapshot of Bitcoin's price. According to Polymarket's changelog, on Aug. 7 the platform switched crypto up/down markets to Chainlink-computed averages. Both the opening price to beat and the final settlement value now use the applicable time-weighted average price (TWAP) feed. On Aug. 14 at 00:00 UTC, the platform extended five-minute crypto markets to 60 seconds.
The current design, as sampled in an Oct. 27 contract covering 12:20–12:25 p.m. ET, names Chainlink's BTC/USD 60-second TWAP as its resolution source. Up wins when the ending benchmark is at least as high as the opening benchmark; Down wins otherwise. This means the contract compares two 60-second averages rather than single-price snapshots.
Earlier Research and the New Study
A working paper by Dai, Jia and Yu, submitted to arXiv on June 30, reported settlement-time spot-flow spikes and subsequent reversals after the five-minute contract's launch. That research also estimated that about $8.2 million was earned by 821 wallets in earlier pushed cycles. Wang's newer study cites that finding.
Wang examined Binance one-second data from July 1, 2025, through Sept. 4, 2026, covering 82,752 Bitcoin boundaries where only the five-minute contract settled. For each sampled five-minute window, he measured the share of Binance volume traded in its final ten seconds. The results show a clear change across regimes:
- Before five-minute contract launch: 3.05%
- Single-snapshot settlement: 5.68%
- 60-second average settlement: 3.02%
In the first three weeks of the 60-second regime, Wang found no systematic migration into earlier bins and no recurrence of the earlier near-strike reversal pattern. That bounded observation is consistent with the reform's effectiveness for the measured pattern, but it is neither a current wallet-profit audit nor proof that every possible manipulation strategy has disappeared.
Understanding the New Calculation
Under a snapshot rule, an unusually brief move can be important if it affects the selected reference price. Under an average, its contribution depends on how much of the measurement window it influences. The economic question becomes whether the benefit on the prediction-market position exceeds the cost of affecting that average and executing the strategy.
Chainlink's timestamp documentation explains why the time printed on an exchange chart is insufficient. Each underlying report has a validity start and an observation timestamp, but report widths can vary, including when a later report absorbs a gap. The TWAP weights prices by the duration they cover. The average also rolls with the latest observation rather than automatically snapping to a round clock minute. A 60-second TWAP is therefore neither the average price across the entire five-minute bet nor necessarily sixty equally weighted ticks.
Polymarket's documentation says it takes the applicable average for the opening price, just as it does for the closing value. Evaluating a disputed result requires the reference values used at both boundaries, along with the relevant report timing.
What the Old Dollar Figure Cannot Answer
A gain on a prediction-market position and the net return from a strategy involving the underlying asset are different measurements. If moving Bitcoin's reference price requires trading Bitcoin, that leg and its execution costs belong in the profitability calculation. A historical dollar gain cannot be carried into the changed calculation without evidence that the old behavior and economics still apply.
Polymarket Institute distinguishes the decentralized international exchange from Polymarket US, with separate APIs and separately managed data. Talos's Oct. 27 quarterly review highlights its Kalshi integration and points to earlier analysis of potential Polymarket settlement manipulation.
The remaining measurement is financial as well as behavioral: gains and losses under the averaged rule, with the relevant underlying-market trades and execution costs accounted for.
