Wintermute Moves Into Prediction Markets After 2026 Event-Contract Volume Tops $60B
Wintermute, the London-based algorithmic trading firm that handles more than $3.5 trillion in annual volume, said Friday it has begun providing two-sided liquidity in prediction markets. The firm becomes the latest institutional market maker to connect to a sector that has already seen more than $60 billion in trading volume in 2026.
In a blog post, Wintermute said it is now quoting continuous bid and offer prices across event contracts on major venues, pointing to more than $20 billion in combined monthly volume across those platforms as of early 2026. A person familiar with the matter told Decrypt that the venues include Polymarket and Kalshi, the two largest event-contract platforms.
Wintermute emphasized it is participating as a market maker, not a bettor. Its focus is on posting two-sided quotes to narrow spreads and absorb larger orders rather than taking directional views on outcomes.
The move brings a top-tier crypto liquidity provider deeper into a market that has evolved from a political-betting niche into a derivatives-style venue for trading real-world event risk.
Kalshi and Polymarket volumes surge
Combined monthly global trading volume on Kalshi and Polymarket rose from under $5 billion in September 2025 to about $24 billion in April 2026, according to a Pew Research Center analysis of data from The Block. The two platforms' lifetime trading volume surpassed $150 billion in April, with Kalshi posting a record $14.81 billion in monthly notional volume and Polymarket clearing $9.01 billion.
Sports account for most of Kalshi's activity — 80% of its volume since July 2024 — while Polymarket is more diversified, with politics at 32% and crypto at 20%, the Pew analysis found.
"Prediction markets have the demand profile of a major asset class but the liquidity profile of an early-stage one," Jake Ostrovskis, Wintermute's Head of OTC Trading, said in the company statement. He added that sustained two-sided liquidity is required for these markets to serve as a reliable real-time signal of probabilities, arguing that deeper order books can tighten spreads, support larger trade sizes, and improve the information embedded in prices.
Not the first institutional market maker
Wintermute joins Jump Trading and Galaxy Digital, which already provide liquidity in event contracts, according to The Block. The addition of another top-tier provider — one that processes more than $3.5 trillion annually across spot, derivatives and DeFi — signals that professional market makers increasingly view event contracts as a new derivatives frontier rather than a side bet.
Regulatory developments the same day underscored the sector's institutional trajectory. The CFTC on Friday cleared Kalshi to offer Bitcoin perpetual futures in the U.S., pushing the platform further into traditional derivatives territory. Separately, Defiant reported that Polymarket recently struck a Nasdaq Private Market partnership tied to event contracts on private-company valuations.
Risks that could slow momentum
Regulatory scrutiny is rising alongside volumes. Spain on May 26 ordered ISP-level blocks on both Polymarket and Kalshi over unlicensed-gambling concerns, the fifth country to take action against the platforms in 2026 following Brazil, Indonesia, India and Portugal.
In the U.S., a New York Times investigation reported that CFTC officials who raised internal concerns about prediction markets were suspended and removed from the agency.
The platforms also differ in regulatory posture. Kalshi is CFTC-regulated and U.S.-only. Polymarket International — the offshore venue that represents most of the company's volume — is not CFTC-regulated. Polymarket US, newly CFTC-approved, cleared $1.3 billion in April 2026 versus roughly $9 billion at the international venue, according to Pew.
For Wintermute, the opportunity remains attractive as long as event-contract volumes continue compounding at the pace seen over the past eight months. Ostrovskis described liquidity as "early-stage," a dynamic that typically implies spreads are still wide enough for market makers to justify stepping in.
