Polymarket and Kalshi post conflicting Anthropic IPO probabilities
Polymarket traders price Anthropic at 63 percent to top SpaceX as 2026's largest IPO, while Kalshi's separate market gives a 90 percent probability for an Anthropic IPO this year. The divergence leaves the two CFTC-regulated platforms with no shared benchmark for the same underlying event. Polymarket's contract ranks Anthropic against SpaceX by deal size; Kalshi's offers a standalone yes-no on whether Anthropic lists at all. Neither market reveals fillable orders or post-trade size data.
The gap matters because no trader can arbitrage it. Polymarket and Kalshi operate disconnected contract structures, so a 63 percent versus 90 percent divergence is not a mispricing to exploit but a signal that the two venues are pricing different questions. That fragmentation hurts anyone building systematic strategies across prediction markets, since portfolio-level risk tools treat correlated contracts as hedges that do not actually move together.
For institutional capital eyeing prediction markets as an alternative data layer, the split raises a due-diligence problem: which venue's methodology governs a position. Polymarket's ranking contract and Kalshi's binary contract will resolve differently even if Anthropic lists, so traders sizing on headline odds alone risk silent basis mismatch. The real consequence is market-structure opacity, not trading edge.