Updated Jun 16, 2026, 12:01 p.m. Published Jun 16, 2026, 11:45 a.m. 2 min readSummaryWorld Cup debutant Cabo Verde held tournament favorite and European champions Spain to a 0-0 draw. The upset produced one of Polymarket’s wildest swings, as a new wallet called “fishalive” turned about $4 million into roughly $9 million in profit by betting Spain would not win and Cabo Verde would stay within 2.5 goals.Another Polymarket trader, “betoor619,” lost nearly $1 million backing a Spain victory for a potential gain of only about $85,000, underscoring both the risks of heavy favorites and the scrutiny on anonymous, onchain betting.FIFA World Cup debutants Cabo Verde held favourites Spain to a goalless draw on Monday, creating an outsized win for punters in a match that started with 1:10 betting odds against the minnows.The result produced two of the most extreme outcomes crypto-based predictions platform Polymarket has seen this tournament. A brand-new wallet turned about $4 million into a profit of more than $9 million in a few hours, Polymarket data reviewed by CoinDesk shows. Meanwhile, another trader lost close to $1 million in a trade that would net just $85,000.Cabo Verde was playing in its first World Cup with no high-profile professionals, while Spain was a pre-tournament favorite and the reigning European champions. Cabo Verde's 40-year-old goalkeeper Vozinha was named player of the match.The winning account, which went by the name 'fishalive' and was created this month, made two bets against Spain, according to on-chain analytics firm Lookonchain. It wagered that Spain would not win the match outright and that Cabo Verde would stay within 2.5 goals, or a "spread bet."When the game ended 0-0, both paid out. The wallet redeemed about $4.7 million on the Spain market and $8.5 million on the spread, per its public trading record, for a one-day profit of roughly $9 million. On the other side, a trader using the name 'betoor619' lost nearly $1 million, Polymarket's trading records reviewed by CoinDesk show. The bettor had put almost $1.1 million on a Spain win when the market priced the favorite at about 92%. Had Spain won, the payout would have been only about $85,000, the thin reward typical of betting on near-certain outcomes.The account had never won or lost more than $9,000 on a single event before, history tied to the account shows.Polymarket is a prediction market where people trade shares tied to real-world outcomes, with prices that act as implied odds and settlement in USDC, a dollar-pegged stablecoin, on a public blockchain.Traders use crypto wallets and operate under pseudonyms rather than real names, a feature lawmakers have criticized because the platform does not collect the background information regulated sportsbooks do. About $64 million traded on the Spain match alone. Polymarket's market on the overall tournament winner has drawn about $2.4 billion, making the World Cup its biggest event since last year's U.S. election and pushing it past the roughly $1.4 billion wagered on this year's Super Bowl.However, the same transparency that lets anyone bet anonymously also leaves a public trail. As every position settles onchain, outsiders could watch 'fishalive' turn a few million dollars into nine in real time, and could ask how a days-old account knew to bet so heavily against a 92% favorite.While the identity might be shrouded in mystery, expect the anonymous account to now garner a cult following in the hopes of future winning trades.12345678910