Market insights

How big are prediction markets now?

Combined monthly trading volume on Kalshi and Polymarket rose from $0.81 billion in July 2024 to $52.99 billion in July 2026, according to Pew Research Center’s analysis of data from The Block. Sports drove most of the recent jump. These are industry figures, not 369X data.

Monthly volume, July 2024 to July 2026

Historical snapshot. Notional taker volume: each contract traded by a taker is counted at its $1 value if correct, not at the price paid. Scope: Kalshi plus Polymarket, with Polymarket figures including Polymarket US. Global. All categories, including sports. Source: Pew Research Center analysis of data from The Block, accessed September 2026; published 23 September 2026. This is not 369X data.

Show all 25 monthly values

Combined monthly notional taker volume, Kalshi and Polymarket (US dollars)
Month	Volume
July 2024	$0.81 billion
August 2024	$0.89 billion
September 2024	$0.89 billion
October 2024	$4.55 billion
November 2024	$4.74 billion
December 2024	$3.47 billion
January 2025	$2.83 billion
February 2025	$1.72 billion
March 2025	$1.74 billion
April 2025	$1.77 billion
May 2025	$1.94 billion
June 2025	$2.11 billion
July 2025	$2.02 billion
August 2025	$1.98 billion
September 2025	$4.51 billion
October 2025	$8.50 billion
November 2025	$10.14 billion
December 2025	$11.98 billion
January 2026	$17.49 billion
February 2026	$18.64 billion
March 2026	$24.27 billion
April 2026	$25.08 billion
May 2026	$25.66 billion
June 2026	$47.75 billion
July 2026	$52.99 billion

What the series shows

Three phases. A spike around the US election in October and November 2024, a quieter first half of 2025, then sustained growth from September 2025. Volume roughly doubled between May 2026 ($25.66 billion) and July 2026, mostly from sports: in June and July, during the FIFA World Cup, sports trading topped $58 billion on Kalshi and neared $22 billion on Polymarket.

Volume, TVL and open interest are different things

Notional volume: Contracts traded, each counted at its $1 payout value. A 10¢ contract counts as $1. This is what the chart measures.
Cash volume: What traders actually paid. Always lower than notional volume.
Open interest: The value of positions still open at a moment in time.
TVL: Total value locked: funds deposited in a protocol’s contracts. A DeFi measure, not a trading measure.
Revenue: Fees a venue keeps. A small fraction of any volume figure.

Mixing these up is the most common error in prediction-market headlines. A venue with $50 billion of notional volume does not hold $50 billion.

Where 369X thinks the gaps are

This is 369X’s own reading, not data. Sports dominate volume, which suits user-requested markets on leagues the big venues don’t list. Communities outside the US and Europe are often restricted or unserved. And order books thin out on niche questions, where an automated market maker can still quote. Whether 369X captures any of this is unproven.

Methodology

Values are copied from the chart data table published with Pew Research Center’s 23 September 2026 analysis. Polymarket figures include Polymarket US.
The series is left as published. No other dataset is added to it, because other sources count volume differently.
Refresh: review monthly. Stale data keeps its original retrieval date.

Pew Research Center: Prediction markets’ trading volume doubled between May and July, largely driven by sports (opens in a new tab)Page dated 23 September 2026. Used for: Monthly combined Kalshi + Polymarket notional taker volume, July 2024 to July 2026 (data from The Block).