Polymarket dispute: trader alleges $500K loss over Strategy BTC sale rules

A Polymarket trader claims the platform “scammed” him into a ~$500,000 loss tied to MicroStrategy (now Strategy) selling Bitcoin before a May 31 deadline. The market contract required a “Yes” outcome only if Strategy sold any BTC by 11:59 ET on May 31, using on-chain data, disclosures, and credible reporting. Strategy filed an 8-K on June 1 stating it sold 32 BTC (about $2.5M) between May 26 and May 31—within the stated resolution window. However, the trader argues Polymarket effectively changed the interpretation after the fact, adding that “confirmation” occurring after the market’s timeframe would not qualify. The market later resolved to “No,” and the trader says this outcome violates the original rules. The trader says he increased his “Yes” position after observing a large BTC transfer (around $30M) to Coinbase Prime a week earlier, which raised expectations that sales were underway. He claims Polymarket’s later clarification should have forced an alternate resolution or a May 31 close if post-deadline confirmation were disallowed. Separately, other Polymarket users criticize the dispute mechanism: after a bond is posted, UMA token holders vote during the resolution debate window, which critics say can create opportunities for manipulation by “UMA whales.”