Polymarket’s prediction market on whether the US will announce a blockade on Iran by December 31 surged 20.0 percentage points over the past 24 hours, lifting the YES contract from 42.5% to 62.5%. This sharp repricing reflects a significant shift in market sentiment within a single day.
Supporting the price move, whale investors contributed a net $28K into YES contracts, with $43K in whale buy volume against $15K in sell volume. The alignment of whale flow with the rising price indicates that large traders are reinforcing the market’s increased probability of a blockade announcement.
The 24-hour trading volume on Polymarket for this contract was $43K, a notable figure relative to its lifetime volume of $400K and a base of 611 unique traders. This level of activity underscores heightened interest and conviction in this geopolitical event.
Interestingly, the Polymarket YES price of 62.5% contrasts sharply with the Polydata on-chain mid-price of 25.5%, suggesting some discrepancy between the prediction market’s spot price and on-chain data aggregation.
The combined picture of a significant 20 percentage point price increase accompanied by strong whale buying indicates a coordinated reassessment of the blockade’s likelihood, signaling growing confidence among large investors in this outcome by year-end.
| Market | Will the US announce a blockade on Iran by December 31? |
|---|---|
| Market ID | 2643406 |
| 24h price change | +20.0 pp |
| YES now (PM Breaking) | 62.5% |
| YES ~24h ago (est.) | 42.5% |
| YES (Polydata overview) | 25.5% |
| Whale net flow (24h) | $28K |
| Whale buy / sell (24h) | $43K / $15K |
| Unique whales (24h) | 107 |
| Volume 24h (PM) | $43K |
| Unique traders (Polydata) | 611 |
Source: Polydata API v3 · /whales/flow + Polymarket Breaking · snapshot 2026-07-12. Data: Polydata API v3. On-chain figures are public. Realized PnL is computed over resolved markets only and excludes open positions, so it is conservative versus the Polymarket UI. This is not investment advice.