Polymarket traders push Anthropic IPO odds to December, Nasdaq favored
Polymarket traders have repriced Anthropic's initial public offering toward December 2026 from November, with Nasdaq emerging as the favored exchange. The shift comes amid a broader rally in artificial intelligence stocks. The platform also runs contracts on which company will produce the best AI model in 2026, where Anthropic is currently the heavy favorite according to the odds. Both markets sit in a non-political vertical that Polymarket has been building out this month.
The repricing spotlights a structural flaw traders cannot hedge away. Polymarket and Kalshi are answering different questions with incompatible contract designs, so the headline odds that circulate on social media and in portfolio dashboards do not describe the same payoff. A trader who sees 60% on Polymarket and 55% on Kalshi and treats the gap as arbitrage owns two unrelated bets. The December-November shift on Polymarket itself is thinly traded, so a single large order could move the implied timeline without genuine information.
For institutional capital using prediction markets as alternative data, this means every Anthropic quote now requires a venue-specific methodology filter or unmeasured basis risk. The real cost is analytical overhead: traders must reconstruct payoff functions before sizing positions, slowing execution. If Polymarket's AI vertical draws repeat engagement, Kalshi and ForecastEx will face pressure to list their own timelines or cede the space. The first venue to standardize contract language across AI events could capture the institutional flow now scattered.