The prediction market platform Polymarket has officially closed the controversial market on whether Strategy would sell any Bitcoin by May 31, ruling in favor of the ‘No’ outcome after a final review by the UMA community. The decision was backed by 98.6% of the voting power, ending a lengthy dispute that had already seen two prior ‘No’ resolutions challenged by traders.
The conflict arose when Strategy disclosed in a June 1 regulatory filing that it had sold 32 BTC, worth about $2.5 million, between May 26 and May 31. This sale occurred before the market’s deadline, prompting traders who had bet ‘Yes’ to argue that the event had actually taken place within the specified timeframe. However, Polymarket had added a note to the market page days before the final review, stating that confirmations made outside the market’s period would not be considered valid. This clarification became central to the debate, with critics claiming it changed the rules after bets had been placed.
One prominent trader, 0xDinosaur, who held a large ‘Yes’ position, argued on social media that the contract language did not require public disclosure of the sale before the deadline. He acknowledged that his position was aggressive but insisted that the platform could not retroactively apply unwritten rules. Another trader, willo2, lost $500,000 after placing ‘Yes’ bets on June 1, alleging the market remained open even after information about the sale emerged. He argued that UMA voters were compelled to follow Polymarket’s rules, which had been altered to favor the ‘No’ outcome.
Beyond individual losses, the dispute has ignited broader discussions about how prediction markets should handle events that occur before a deadline but are only publicly confirmed afterward. Galaxy Research commented that the core issue is whether the original event-based rules or the post-trade clarification should prevail. The firm emphasized that prediction markets should focus on the actual occurrence of events rather than after-the-fact reinterpretations by oracles. It suggested that clearer listing criteria and deterministic resolution methods could prevent similar controversies in the future.