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Y Combinator Backs $8.5 Million Seed Round to Build Prediction Market Trading Tools for Institutions
August 16, 2026 · 1 min read
Prediction markets are moving beyond the gambling debate—and the latest signal is where serious venture capital is going.
River Markets (YC P26) has raised an $8.5 million seed round led by Haun Ventures, with Y Combinator and Coinbase Ventures participating alongside angels from Google, Nvidia, JPMorgan, and Citadel.
The founders bring serious institutional trading experience. Oscar Levy previously worked as a VP quant at BlackRock, while Antonin Parrot worked in electronic and high-frequency trading at Morgan Stanley. The two met at Berkeley through poker and Japanese stock trading before building trading bots for Kalshi and Polymarket. Those systems reportedly generated seven-figure returns before the pair turned their experience into a company.
River Markets is building an institutional trading terminal designed to bring fragmented prediction markets into a single interface. The platform aims to provide cross-venue execution, risk management, and algorithmic trading tools that can help institutions execute larger positions without significantly moving market prices.
That infrastructure addresses one of the biggest challenges facing prediction markets today: liquidity and positions are spread across multiple venues, making it difficult for professional traders and funds to manage exposure efficiently.
The broader institutional trend is becoming harder to ignore. Kalshi has reported an 800% increase in institutional volume over six months, while hedge funds are increasingly treating prediction markets as financial instruments for trading and hedging real-world risks, including GPU rental prices.
The important signal isn't simply that another prediction market startup has raised money.
It's that capital is now flowing into the infrastructure around prediction markets—trading terminals, execution systems, risk management, and institutional tooling.
That's what happens when an emerging market starts becoming a real financial ecosystem.