Polymarket US Hits $8.7B, Plus Coinbase and Roundtable on Paying Media in Minutes

• Polymarket US volume up roughly 30x since January, driven by sports
• Coinbase now distributes both Kalshi and Polymarket
• Real-time stablecoin payouts for publishers instead of 90-day terms
• Agentic trading and Coinbase’s x402 platform
• Tokenization as the forcing function for mainstream adoption

Summary

Kelvin Sparks breaks down Polymarket US’s $8.7 billion September and Coinbase’s move to carry both major prediction market venues, then sits down with Roundtable CEO James Heckman and Coinbase Institutional Head of Strategy John D’Agostino to discuss real-time stablecoin payouts for publishers, agentic trading, and why tokenization will drive mainstream adoption.

Recording from Token2049 in Singapore, Kelvin opens with the month in prediction markets. Polymarket US, the CFTC-regulated exchange, went from about $280 million in January volume to $8.7 billion in September, roughly 30 times bigger in eight months and more than double the international platform, with sports driving almost all of it. The October Fed hike market climbed from about 26% on September 1 to roughly 69% by September 29, then fell to just under 20% after comments from New York Fed president John Williams, soft inflation data and a September jobs report showing 29,000 new jobs, with more than $26 million traded along the way. Coinbase now carries Kalshi in its main US app and Polymarket in its wallet for non-US users, making it a distribution layer for event contracts that takes flow whichever venue wins. Kelvin also covers Polymarket’s new head of institutional growth, a former Goldman Sachs partner, and why the World Cup still outpaces NFL Sundays on volume.

In the interview, Heckman explains how Roundtable is moving hundreds of media brands onto shared blockchain infrastructure. Publishers, including major outlets, often wait 60 to 90 days to be paid on ad sales. Roundtable’s on-chain reporting tracks revenue per view in real time and settles it in USDC through publishers’ Coinbase accounts, which also turns those receivables into collateral. He says sports reporters on the platform now pay themselves by the hour, and recalls UK media executives asking whether they would be forced to take crypto.

D’Agostino says Coinbase is watching agentic trading grow through its x402 platform, but expects trust to take longer than the technology. He argues stablecoins have been crypto’s big success story since the GENIUS Act, that regulators filled the gap after the Clarity Act failed, and that crypto needs to stop equating volatility with risk. He frames tokenization as a forcing function for adoption, explains why on-chain collateral opens up credit and yield, and says media companies are responding to cash flow pressure and debanking fears.

About the guests
James Heckman is the founder and CEO of Roundtable, a Nasdaq-listed media platform built on DeFi and AI, and a media technology veteran who previously led digital strategy for News Corp and Yahoo.

John D’Agostino is Head of Strategy for Coinbase Institutional and the former Head of Strategy at the New York Mercantile Exchange, where he led the effort to build the first Middle East energy derivatives exchange with the Dubai government, a story told in Ben Mezrich’s bestseller Rigged.