The size war between Calci and Polymarket extends to public opinion. In the new appeal, executives are now openly arguing about how big the market really is and what counts as “real” business. This comes as prediction markets face continued scrutiny over multiple instances of insider trading emerging on platforms.
John Wang, head of crypto at Calci, rejected claims that the two platforms achieved roughly the same trading volumes in March. In a post, he said Calci processed $13 billion in March, while Polymarket handled nearly $10 billion. He tried to clear the air on conflicting estimates that put both at closer to $12 billion.
Kalshi claims up to 70% turnover on the best Polymarket markets
Wang said comparisons often ignore structural differences between platforms. He suggested that a fair comparison be made Polymarket US size Because it is largely focused on sports. The head of the crypto division at Calci put Man of Steel’s name Spencer in the middle and called him Polly Panama.
In X mailHe stated that even within Polymarket’s core markets, further adjustments are needed. Wang noted that war-related contracts account for a large share of Polymarket’s political volume. However, this is a category that Calshi does not offer. If this section were separated, it would fundamentally change the comparison.
Wang also raised concerns about data quality. He claims that wash trading accounts for up to 70% of activity on some of Polymarket’s top markets. At the same time, this number is difficult to verify.
Another Kalshi member came to support this claim. He stated that the numbers shared publicly “were somewhat inaccurate. However, he cited Dune’s dashboard data showing Polymarket’s trading volume at about $9.5 billion in March. This number is very low compared to Kalshi’s $13 billion.”
Total trading volume for Kalshi and Polymarket was roughly even in March at roughly $12 billion each. Eliminate sports and the picture will be different.
Polymarket made $7.5 billion in non-mathematical volume. Kalshi made $1.6 billion.
It’s strange that they are in the same category given their completely different placement… pic.twitter.com/XR0nHgoYE1
-Spencer Bogart (@CremeDeLaCrypto) April 26, 2026
As of April 2026, Calci has surpassed Polymarket in total trading volume. The platform has established itself as a market leader with approximately $37.5 billion in notional volume year-to-date. Meanwhile, Polymarket was valued at approximately $29.2 billion.
The debate comes as prediction markets are rapidly expanding into a multi-billion dollar sector. On the other hand, they also face high regulatory and legal pressures.
Prediction markets are facing heat due to instances of insider trading
The most high-profile case came to light this week. US prosecutors Gannon reportedly accused Ken Van Dyke of using secret intelligence to bet on Polymarket. Bets were related to Nicolas Maduro arrested. Authorities allege the deals generated profits of more than $400,000.
At approximately the same time, Calci revealed that it had imposed fines and suspended three congressional candidates for betting on the results of their elections. This raises similar concerns about insiders’ access to information.
Regulatory bodies are also starting to take a tougher stance globally. In Brazil, the Brazilian Central Bank has moved to block prediction markets entirely. He pointed to the risks that threaten investor protection and market integrity. Restrictions apply to contracts linked to events such as politics, sports and social outcomes.
The United States is witnessing a wave of criticism that has become more direct. Donald Trump said he was “not happy” with prediction markets. He described them as “a bit of a casino”. However, these platforms continue to frame their products as financial instruments rather than bets.
This distinction is now being tested. A complaint in Wisconsin targeting companies including Kalshi and Polymarket says their marketing materials resemble gambling services more than regulated financial products.
Despite the scrutiny, both platforms continue to expand. Kalci says its cryptocurrency markets have grown rapidly in recent months, with volumes increasing nearly 10-fold, while Polymarket remains dominant in cross-chain global event trading.
The CFTC appears to be moving forward from trying to ban certain event contracts to actively asserting its “exclusive jurisdiction.” On March 12, 2026, the agency began the formal process of building a framework for prediction markets. It requested public input on whether event contracts should be classified as “swaps” or “futures”.
