Category briefing · prediction markets
Prediction markets: volumes, trends & regulation
Prediction markets just printed their biggest numbers on record. Here is how big the category has become — combined venue volumes, the World Cup spike, and the ETF regulatory story — with every external figure cited and dated. Then, links to watch the live markets yourself.
External figures re-verified 2026-07-17. Each is attributed below.
How the category got this big
A prediction market is a real-money market on a yes/no question, and for years the category was a niche. That changed fast. By mid-July 2026 Kalshi and Polymarket had together crossed roughly $150B in cumulative trading volume, and in June the major platforms combined topped $50B in a single month for the first time — a ~75% jump from May (CoinDesk, cited above). The engine of that spike was sport: the 2026 FIFA World Cup, widely described as the biggest gambling event in history.
The World Cup spike
Kalshi alone recorded more than $31B in notional volume in June (up ~70% from May), with its World Cup markets accounting for about $7.4Bof that — more than its entire March Madness figure — before the group rounds were even complete. Polymarket's international platform hit a record $10.8B, and its regulated US platform did about $3.5B. You can watch the live winner-market probabilities that sit under those volumes on Monitoring's World Cup tracker — the final is Sunday 19 July.
The regulatory story
Scale brought scrutiny. US regulators are weighing whether event-contract prediction markets belong inside products built for fund investors, which has delayed planned prediction-market (event-contract) ETFs, while several jurisdictions have moved to block or restrict access. This is public regulatory context, not a verdict: Monitoring reports what is happening, and this page is information, not legal or investment advice. For the detail — the CFTC-versus-states jurisdiction fight and the state-by-state status — see is Polymarket & Kalshi legal.
What Monitoring shows — and what it doesn't
Monitoring does not set prices, take positions, or predict outcomes. The category volumes above are cited to named external sources with an as-of date. Monitoring's own live numbers — the implied probabilities on each tracker, and the site-wide Monitoring Situation Index — render live from public market and event data, so they are never restated as a fixed figure here. If you are new to reading a market, start with how prediction markets work. And to see what markets priced before an event resolved — recorded in advance, with sources — see the accuracy ledger.
Market-integrity watch
As the category has scaled, so has the reporting and research on how these markets are regulated and policed. Below is a round-up of that third-party coverage — each item summarised, attributed to a named source, and dated. Monitoring is reporting what others have published; it is not making any finding of wrongdoing about any person or platform. For Monitoring's own record of what markets priced before events resolved, see the accuracy ledger.
Sources re-verified 2026-07-24. Each links to its origin below.
Who should regulate prediction markets?
Bloomberg published a video explainer, “How Should Prediction Markets Like Kalshi and Polymarket Be Regulated?”, laying out why US states and the federal CFTC disagree over who has authority, how courts have responded to a wave of lawsuits, and how the outcome could reshape sports betting and event contracts.
Source: Bloomberg (video) · as of 2026-07-23
Polymarket files to offer margin trading in the US
CoinDesk reported that Polymarket filed applications with the National Futures Association — through an affiliate — seeking to register as a futures commission merchant and offer regulated margin (leveraged) trading to US users. The reporting notes the plan would still require CFTC sign-off.
Source: CoinDesk · as of 2026-07-10
Bloomberg “Big Take” on insider-trading scrutiny
A Bloomberg “Big Take” investigation reported that a review flagged tens of thousands of trades on Polymarket between August 2025 and June 2026 as potential insider activity, and examined what it would take for regulators to respond. Bloomberg frames this as a reporting finding, not a legal determination.
Source: Bloomberg (Big Take) · as of 2026-07-20
Stanford working paper on settlement manipulation
As reported by Bloomberg, a working paper by researchers at Stanford and Singapore Management University found statistical patterns consistent with settlement manipulation in short-horizon (five-minute) Bitcoin prediction contracts on Polymarket, estimating a small group of traders profited about $8.2M, and suggested longer settlement windows as a fix. It is a preprint, not peer-reviewed.
Source: Bloomberg (on the Stanford / SMU paper) · as of 2026-07-15
This round-up is information and entertainment only — not legal, financial, or betting advice, and not a claim by Monitoring about any named individual or company. Follow each link for the original reporting or research.
Trading-volume and market-implied figures on this page describe public real-money prediction markets and are attributed to named external sources with an as-of date — they are observations, not forecasts by Monitoring, and not an endorsement of any outcome, platform, or product. This page is information and entertainment only: it is not betting, financial, or legal advice, not a recommendation to wager, and not affiliated with any exchange or bookmaker.