---
title: "Prediction Markets Hit Record $123.6B Notional Volume in October, a16z Says"
description: "Monthly contract turnover rose 58% month-over-month to surpass total combined volume from 2024 and 2025."
url: https://basisdesk.news/news/prediction-markets-october-record-volume-kalshi-polymarket
published: 2026-11-05T21:21:16.916Z
modified: 2026-11-05T21:21:16.916Z
section: DeFi
author: Basis Desk Newsroom (AI-generated, source-verified)
sentiment: bullish
tickers: [BTC, ETH]
tags: [prediction-markets, polymarket, kalshi, trading-volume, a16z]
license: Quote with attribution to Basis Desk (basisdesk.news). Not financial advice.
---

# Prediction Markets Hit Record $123.6B Notional Volume in October, a16z Says

Monthly contract turnover rose 58% month-over-month to surpass total combined volume from 2024 and 2025.

## At a glance

- **What happened:** Prediction markets posted a record $123.6 billion in monthly notional trading volume in October 2026, according to a16z crypto.
- **Why it matters:** The volume surpassed all of 2024 and 2025 combined, with platform web traffic reaching parity with mainstream news publishers like Bloomberg.
- **Who is affected:** Prediction market participants, event contract traders, and market operators Kalshi and Polymarket.
- **What's next:** No next step announced.
- **Primary source:** [Prediction markets’ biggest month yet, in 3 charts](https://a16zfrontier.com/posts/article/prediction-markets-biggest-month-3-charts/) — a16z crypto

## Key points

- Prediction market notional trading volume reached a record $123.6 billion in October 2026, rising 58% from September [1].
- Cash paid into contracts hit $22.7 billion during the month, surpassing the $20.9 billion recorded throughout all of 2025 [1].
- Polymarket and Kalshi drew 38 million and 28 million October web visits, rivaling established media properties such as Bloomberg and Politico [1].

## Editorial remark

- **Context:** Event contracts set successive monthly volume highs in September before surging further in October, driven by heavy participant engagement across political, macroeconomic, and cultural markets.
- **Impact:** Market operators collected $647 million in monthly fees, while the web footprint of leading platforms now rivals mainstream digital news publishers, repositioning markets as primary data feeds.
- **Watch:** Platform retention and trading volume metrics in post-election cycles, alongside open interest figures following the resolution of October's contract cycle.

Prediction markets registered an all-time monthly high in October 2026, generating $123.6 billion in notional trading volume, according to a report published on Nov. 5 by venture firm Andreessen Horowitz's a16z crypto [1]. The monthly total represents a 58% increase compared to prior records set in September and exceeds the combined $82 billion in notional volume recorded across all of 2024 and 2025 [1]. 

Under a cash-paid measurement—which calculates contract costs rather than eventual payouts—traders deployed $22.7 billion in capital during October, representing a 25% month-over-month increase [1]. This metric also surpassed the $20.9 billion deployed across the entire year of 2025 [1]. In total, participants executed 644 million trades across platforms, up 36% from the prior month, while generating $647 million in fees and pushing open interest to $3.1 billion [1].

## Web Traffic Rivals Established News Outlets

The surge in market activity coincided with a notable shift in online attention, with platforms functioning increasingly as direct information sources [1]. Platform web traffic tracked by Similarweb showed Kalshi drawing 28 million site visits and Polymarket securing 38 million visits throughout October [1]. These traffic figures put the platforms on par with conventional media organizations, matching Bloomberg's 38 million visits and surpassing Politico's 32 million visits over the same timeframe [1].

The figures underline expanding consumer adoption for event derivatives, continuing momentum seen as [Prediction Markets Kalshi and Polymarket Face Midterms Test as Volume Surges](https://basisdesk.news/news/kalshi-polymarket-midterms-test-trading-volume-surge). The elevated activity in event contracts arrives despite broader softness across digital asset markets, where $BTC traded around $75,896 and $ETH stood at $2,234 at the time of writing.

## Sources

1. [Prediction markets’ biggest month yet, in 3 charts](https://a16zfrontier.com/posts/article/prediction-markets-biggest-month-3-charts/) — a16z crypto, 2026-11-05

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Basis Desk Newsroom · AI-generated, source-verified · https://basisdesk.news/about/how-we-use-ai