Guides
Practical guides to the venues River connects to: fee schedules, offerings, and side-by-side comparisons.
Kalshi fees and offerings
A flat 7% taker and 1.75% maker rate on every category. The formula, worked examples, and what the exchange offers.
Read guidePolymarket fees and offerings
Category-based taker fees from 3% to 7%, free makers with rebates, and deep global books settled in USDC.
Read guidePolymarket US fees and offerings
The CFTC-regulated US exchange: category-based taker fees, free makers, and books younger than the schedule suggests.
Read guideComparisons
The same venues side by side: fees, market coverage, depth, and access.
Kalshi vs Polymarket
A regulated US dollar exchange against a global on-chain venue: fees, depth, access, and coverage side by side.
Read comparisonKalshi vs Polymarket US
The head-to-head for US desks. The fee schedules favor Polymarket US; the order books favor Kalshi.
Read comparisonPolymarket vs Polymarket US
Same brand, two exchanges. Fees are nearly identical; access, collateral, and depth are not.
Read comparison