River Markets raises $8.5M seed
Announced 1 July 2026
◆ The Round
River Markets raised $8.5M in seed funding, announced on 1 July 2026, led by Haun Ventures, with participation from Y Combinator, Coinbase Ventures, Qube Research Technologies. The round is tracked live by Fusion42 as part of the Raise fund database and the Scout startup database.
◆ About River Markets
A San Francisco-based startup building a prime brokerage layer for prediction markets that aggregates access to multiple venues including Kalshi, Polymarket, and others into a single institutional trading platform. River Markets is based in United States and currently at seed stage, operating in Fintech.
◆ Investors
LeadHaun Ventures
ParticipationY Combinator, Coinbase Ventures, Qube Research Technologies
◆ Investing funds on Raise
◆ Market context
Haun Ventures, Y Combinator and Coinbase Ventures are profiled on Raise, Fusion42's database of venture funds — where each investor's thesis, cheque size and other tracked backings can be followed. This funding event is a citable node in Fusion42's market graph: it links River Markets's Scout profile to the funds behind the round and to related Wire analysis, and is refreshed from public announcements as the round is confirmed or extended. It is the same live market data Arthur reasons over when benchmarking a founder's own raise against what is closing in the market right now.
◆ Explore the market
◆ FAQ
How much did River Markets raise?
River Markets raised $8.5M in its seed round, announced 2026-07-01.
Who invested in River Markets's seed round?
The round was led by Haun Ventures, with participation from Y Combinator, Coinbase Ventures and Qube Research Technologies.
What does River Markets do?
A San Francisco-based startup building a prime brokerage layer for prediction markets that aggregates access to multiple venues including Kalshi, Polymarket, and others into a single institutional trading platform.
Verified 13 August 2026 · Sources: public filings