Polymarket US Notional Trading Reaches $13.6 Billion in 30 Days
Key Facts
The notional value of contracts traded on Polymarket US was about $13.6 billion in the 30 days ended October 27, 2026, up 65% from the previous period, according to the DeFi Rate dashboard. That volume represented 11.5% of total trading tracked by the dashboard. Actual payments on the contracts, however, totaled $3.3 billion over the same period, a measure distinct from notional value. The wide gap reflects how prediction-market volumes are calculated: contracts are recorded at their notional value even when the amount paid is lower. The figures come as oversight of the regulated U.S. market intersects with a broader dispute between federal authorities and some states over who supervises prediction markets.
The DeFi Rate dashboard calculates trading volume based on the notional value of each contract, which is $1, and displays dollars actually paid alongside it as a separate indicator. The $13.6 billion figure therefore represents the value of contracts traded on that basis, not cash fully paid to open them. The $3.3 billion figure measures money actually paid on Polymarket US contracts during the same period. Across nine platforms tracked by DeFi Rate, total notional value reached $118.7 billion in the latest 30 days through October 28, compared with $28.7 billion actually paid. The comparison shows that reported figures for the sector depend heavily on the metric used, and that separating notional value from cash flows changes how activity is viewed.
Polymarket operates a separate U.S. platform from its international one, and the company says the U.S. platform is isolated from the other. The international platform is built on blockchain technology and uses cryptocurrencies, while the U.S. platform operates under a more centralized structure, is regulated by the U.S. Commodity Futures Trading Commission and is funded in dollars. That separation places U.S. market activity within a different regulatory framework from international activity, both in operating structure and in how accounts are funded. The company resumed operations in the United States at the end of 2025 after buying derivatives exchange QCEX to obtain the required license. It had moved outside the United States in 2022 after settling federal charges of operating an unregistered derivatives market.
The Commodity Futures Trading Commission’s regulatory record shows that the Polymarket US rule amendment filed by QCEX was approved on April 3, 2026. The commission also announced on March 12, 2026, that it was seeking public comments on whether to amend rules governing event contracts or issue new rules. CFTC Chairman Michael Selig said the announcement “begins a rulemaking process grounded in a rational and consistent interpretation of the Commodity Exchange Act.” The commission says it has exclusive jurisdiction to oversee prediction markets, while some states argue that oversight falls within their remit. The dispute extends beyond any single platform: more than a dozen states are involved in lawsuits over these markets, and the National Football League asked the Supreme Court earlier in October to rule on their regulation.
In sports, the National Basketball Association announced agreements making Polymarket and Kalshi its preferred prediction-market platforms, alongside a memorandum of understanding with the federal regulator. The arrangements include sharing information about investigations and suspicious trading, according to the league. They also include restrictions on market types and a ban on team and league employees trading contracts tied to league events. The league said prediction markets would be required to “share information related to investigations and suspicious trading.” These conditions put integrity and information sharing at the center of the platforms’ commercial expansion in sports, as the dispute over regulatory jurisdiction continues.