A story that once again reminds us of the risky nature of decentralized predictions. An investor under the pseudonym coldsway recorded a colossal loss of $11.63 million on the Polymarket platform by betting against the outcomes of the 2026 FIFA World Cup matches. The entire collapse process took just ten days.
An analysis of Polymarket's open data shows that out of 15 placed bets, only four were successful. The success rate was a modest 26.7%. The remaining 11 positions were completely lost, resulting in the loss of all funds invested in them.
Key bets that led to the disaster
The most devastating blow to the balance was dealt on July 4. A bet against the victory of the Morocco national team resulted in a loss of $4.95 million. This amount was completely wiped out. Other major failures included a bet against Canada's victory on June 28 (loss of $3.1 million) and a bet on Portugal's victory on June 27 (loss of $1.95 million).
The user's total trading volume during this period reached an impressive $48.19 million. However, the net loss from the 11 unsuccessful bets amounted to $15.86 million, significantly outweighing the profit from the four winning positions.
Silver linings amid the devastation
The only bright spot was a bet on a draw in the Australia vs. Egypt match. An investment of $689,000 yielded a net profit of $1.12 million, demonstrating a return of 162.4%. Profits also came from bets on the Colombia national team (-1.5), Croatia's victory on June 27, and a bet against Egypt's win on July 3. The total income from these four trades was $4.23 million, nearly four times less than the overall losses.
This case is a classic example of how an emotional approach and betting against clear favorites can destroy capital in a matter of days. Analytics show that even rare successful trades do not save you from systematic errors in risk management. Polymarket remains a field for cold-blooded analysts, not for gambling fans.