Featured Case study Execution

The hidden 2.4% tax on your prediction market trades

For large prediction market orders, the best displayed price can be misleading. Using a 50,000-contract Fed decision trade, we examine how smart order routing and passive execution can reduce slippage and fees.

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Kalshi Settlement

Kalshi Paid Out the Wrong Side Before the Michigan Game Was Over

What happens when you get the outcome right, but the exchange pays the other side? Kalshi prematurely settled Western Michigan vs. Michigan, then reversed the payouts.

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API Execution

A Unified API for Prediction Markets

Connecting to one prediction-market venue is straightforward. Connecting to several is an infrastructure problem. River's unified API makes Kalshi, Polymarket, and Polymarket US behave like one system.

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Macro Execution

Trading the economic calendar with prediction markets

Economic releases can now be traded as discrete events. The contracts are simple. Building a repeatable strategy around them is not.

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Research LLM

Trading earnings-call mentions using LLMs

Prediction markets already aggregate information into a probability. An LLM should not throw that signal away. Market-Conditioned Prompting combines the market's prior with textual evidence.

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Research Trading

Semantic correlations and how to trade them

A two-stage framework uses statistics to discover candidate lead-lag trades and an LLM to test whether they make economic sense. The main benefit was smaller losses.

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