Recap: Kalshi vs Polymarket on Powell's Departure

The divergence analysis below is from early May 2026.

The rest of this article is what we wrote before the result, kept for the record.

On April 29, 2026, an unusual divergence appeared in the prediction-market world: Kalshi pegged the probability of Jerome Powell leaving the Fed by June at roughly 30%, while Polymarket priced him departing between May 15 and May 22 at 87%, according to CNBC's reporting.

Same broad event. Same news cycle. A 57-percentage-point gap.

Why the Two Markets Disagreed

Three reasons explain most of the spread:

1. The contracts aren't identical

Kalshi's "Powell out by June" contract resolves YES if Powell vacates *either* his chair role *or* his board seat by June 1. Polymarket's contract is narrower — specifically focused on him stepping down between May 15 and May 22 *and* making it official.

Translating between the two requires modeling the conditional probability that, *given* Powell leaves at all, he leaves in that specific one-week window. That's a real but smaller adjustment than the headline gap suggests.

2. Different user bases price macro differently

Kalshi's macro markets attract a more institutional crowd: hedge fund analysts, professional macro traders, policy researchers. They tend to be cautious about pricing in dramatic outcomes without explicit confirmation.

Polymarket's user base skews crypto-native and more reactive to news flow. When Powell's future became a live question, Polymarket priced the *narrative* harder than the *base rate*.

3. Liquidity and skew

Kalshi's macro contracts have deeper books, which means a few large institutional sellers can keep prices anchored. Polymarket markets often have one or two whales who can move prices significantly until counterflow arrives.

Is This an Arbitrage?

Mostly no — and it's important to understand why before you try to capture the spread.

• Different contract terms. As noted above, you'd need to construct a synthetic position that hedges the timing/role differences.
• Different venues. Kalshi and Polymarket US are separate exchanges with separate order books, so the same question can price differently on each.
• Withdrawal timing. Even if you "lock in" a spread, you can't redeploy capital instantly between platforms.

What it *is*: an information edge. When two efficient markets disagree this much, one of them is wrong. Reading both gives you a better prior than reading either alone.

How to Use Cross-Platform Divergence

1. Read both order books before taking a position. If they agree, you're probably not getting an edge. If they disagree, you have a question worth investigating.
2. Identify the cleaner contract. Whichever contract has tighter resolution criteria and deeper liquidity is usually the better one to express your view on.
3. Be skeptical of "free money." Apparent arbitrages on prediction markets almost always have a hidden cost — settlement risk, withdrawal delays, currency conversion, or contract-term mismatch.

Sources

• CNBC, "Kalshi bettors prediction Powell to stay as Fed Governor," April 29, 2026
• Kalshi and Polymarket order book data, April 28–29, 2026

Compare Kalshi and Polymarket head-to-head →

See Top Platforms →

Related articles

• Trading volumes hit $26 billion in January 2026. Here is what is driving growth, who the key players are, and what risks remain.
• A 15-year iGaming industry veteran's honest assessment of John Oliver's HBO segment on Kalshi and Polymarket.
• Primary season is heating up. Senate control markets, individual seat futures, and congressional approval contracts are already generating significant volume. Here is how to read political prediction market prices before November.