Kalshi Posts Record $31 Billion June Volume as 2026 FIFA World Cup Fuels Prediction Markets

Prediction-market trading surged during the 2026 FIFA World Cup, with Kalshi posting a nominal trading volume exceeding $31 billion in June, up from $17.9 billion in May, according to Dune Analytics data cited by CNBC.

“Action Network | Register with the best World Cup prediction market apps and trade with Polymarket vs”

Action Network

Polymarket’s international event contract exchange also set a monthly record, with notional trading exceeding $10.8 billion in June, while its U.S. platform posted more than $3.5 billion for the month compared with $1.77 billion in May.

CBS Sports

CNBC reported Kalshi managed volume over $1 billion daily since the tournament began on June 11, while Polymarket’s volume reversed declines in April and May.

The same reporting said open interest rose alongside the activity, with Kalshi open interest now above $1 billion and Polymarket open interest just under $400 million.

Asaf Meir, CEO at Solidus Labs, said the World Cup is a “key moment” for platforms as regulators and institutions watch whether they can maintain “a level playing field for all investors” in a sustained high-volume environment.

As the Round of 16 played out, Kalshi and Polymarket priced the United States’ tournament win at 4.3% and 3% respectively, with more than $64 million on Kalshi and $122 million on Polymarket traded on whether the U.S. would win the tournament.

CNBC also reported that Polymarket launched a competition to reward up to $2 million for crafting a perfect World Cup knockout round bracket, while Kalshi advertised that users can “Trade the World Cup” in the title of its mobile platform.

CNBC

In a separate guide, Elite Sports NY listed Round of 16 games for July 4, 2026, including Canada vs. Morocco at 1:00 pm ET in Houston and Paraguay vs. France at 5:00 pm ET in Philadelphia.

The same guide said Polymarket is available in over 40 states and that first-time users can claim a promo code ELITE to get an offer to deposit $20 and get a $50 bonus for trading on markets like World Cup games.

Action Network similarly framed the Round of 16 as a time to trade on “Saturday, July 4, 2026,” and it pointed readers to Polymarket and Kalshi sign-up promos including a $20 deposit to unlock $50 in trading bonus funds on Polymarket.

The trading boom has intensified a legal and regulatory debate in the United States, with CNBC reporting that by March nearly a dozen US states had moved against companies including Kalshi and Polymarket.

“The 2026 FIFA World Cup was forecast to be the biggest gambling event in history”

CNBC

CNBC also cited CFTC Chair Michael Selig accusing states of pursuing “illegal enforcement actions” against federally regulated exchanges, adding, “To any state that seeks to nullify federal law and seize authority over these markets, we will see you in court.”

In the same period, casino operators, tribal organizations and labor groups urged Congress to remove sports-event contracts from the CFTC’s authority with an amendment to the Digital Asset Market Clarity (CLARITY) Act, according to the reporting.

Europe has taken a different approach, with ESMA reminding firms that many event contracts may already fall under existing restrictions on binary options and that whether a product is regulated depends on its characteristics rather than the “event contract” label attached to it.

Across the market, platforms also emphasized risk and eligibility, and CBS Sports’ Kalshi guide said event contract trading involves significant risk and is not appropriate for everyone, while listing that Kalshi is available in all 50 states, Washington, D.C. and U.S. territories.