River Markets

River Markets is a prime broker for prediction markets, giving hedge funds and prop desks one execution stack across venues: a multi-book terminal, native execution algos (icebergs, pegs, TP/SL), smart routing that splits fills across Kalshi and Polymarket for about 2 cents average price improvement, and a unified OMS with subaccounts. It raised an $8.5M seed led by Haun Ventures, with Y Combinator and Coinbase Ventures participating.

cryptoY Combinator

River Markets raised $8.5M in a Seed round announced August 9, 2026, according to x.com. Investors in that round: Cherry Ventures, Coinbase Ventures, Haun Ventures, Humbition, Kima Ventures, Qube Research & Technologies, Stack Asset Management, TENET, UFO Holdings, Y Combinator.

Raise history

1. August 9, 2026
   Seed · $8.5M
   Cherry Ventures, Coinbase Ventures, Haun Ventures, Humbition, Kima Ventures, Qube Research & Technologies, Stack Asset Management, TENET, UFO Holdings, Y Combinator
   Source: x.com (source listing)
2. August 9, 2026
   First seen by Recent Funding
   via CoinCarp, Dropstab, Frontrun VC
3. April 14, 2026
   Flagged by Frontrun VC before announcing (117 days early)
   24 tracked investor and founder accounts following on X

Investors

• Cherry Ventures
• Coinbase Ventures
• Haun Ventures
• Humbition
• Kima Ventures
• Qube Research & Technologies
• Stack Asset Management
• TENET
• UFO Holdings
• Y Combinator

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• ParlayX · $1.25M
• MemeBitcoin · $8M
• Polymarket · $1B

Every amount links to the page it came from. How Recent Funding sources and verifies funding data. The same data as JSON: /api/v1/companies/river-markets.