What is the primary difference in fees between polymarket and Kalshi?

The main difference is that Kalshi charges per-contract trading fees for both sides of a binary, with fees varying by price. Polymarket’s fee model may apply differently to each leg and can include varying rebates or penalties. Always check the latest API responses or market pages for current fee details.

Do fees affect end-of-day edge calculations in KalshiArb?

Yes. When you calculate edge, you must subtract all applicable fees from the raw price-based edge. Since Kalshi settles in USD and prices are in cents, even small fee fractions can affect whether a spread remains profitable after fills.

Is there a guaranteed edge if YES + NO prices sum to less than $1?

An edge can exist if YES_ask + NO_ask is less than $1 after accounting for fees, but there is no risk-free guarantee. Fees, slippage, and resolution timing can erode profits. Treat it as a defined edge rather than a guaranteed payout.

Can I rely on polymarket as a substitute for Kalshi for arbitrage?

Polymarket operates on a different, crypto-backed model and settlement, so it’s not a direct substitute for Kalshi’s USD-regulated market. If your goal is a US-regulated venue with a specific edge profile, KalshiArb focuses on Kalshi-based arbitrage while keeping cross-platform comparisons as context.

Fees and Tax

POLYMARKET Fees vs KALSHI: How They Differ for Arb Traders

polymarket fees vs kalshi isn’t just a headline. It frames how much you pay to trade binary contracts on two major platforms in the US-regulated space. If you’re evaluating Kalshi versus Polymarket for arbitrage opportunities, you need to understand how each venue prices trades, how fees scale with price, and how settlement works. This article breaks down the fee structures, then ties them to practical implications for intra-market and combinatorial spreads. Expect concrete contrasts you can map to your own KalshiArb setup.

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How polymarket fees vs kalshi differ in structure

Polymarket and Kalshi both offer binary YES/NO contracts, but their fee models aren’t identical. Kalshi charges a per-contract trading fee that applies to both makers and takers, with the exact amount depending on price and volume. The result is that costs can be higher as contracts trade near the middle of the $0.01–$0.99 range, where price sensitivity and liquidity are typically strongest. Polymarket’s fee structure differs in how it applies to each leg and how it communicates rebates or penalties for liquidity provision. For a trader focused on arbitrage, the key question is whether the combined fees across YES and NO legs allow a risk-defined edge to persist after every fill.

Edge impact on YES/NO price pairs

On Kalshi, every binary market has a YES and a NO side that together sum to $1.00 fair value. When you compare to Polymarket, you also look at how the spread between YES and NO legs translates into potential edge after fees. If polymarket fees vs kalshi create a net cost that erodes the expected $1.00 payoff, your guaranteed profit from a simple lock-in (buy YES and NO on underpriced sides) shrinks. In KalshiArb practice, the algebra is straightforward: assess the combined price of the best YES and NO offers, subtract the platform’s per-contract fees, and see if the residual edge remains positive.

Practical considerations for arbitrage setups

Fee awareness matters for intra-market spreads and combinatorial plays. Kalshi’s pricing and settlement in USD mean you’re watching cents rather than dollars, so even small fee deltas can matter. When evaluating polymarket fees vs kalshi for an explicit arb setup, simulate a full cycle: place paired orders, account for fees, and measure realized edge after fills. This is where KalshiArb’s low-latency alerts and non-custodial workflow help you act quickly before liquidity shifts.

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FAQ

What is the primary difference in fees between polymarket and Kalshi?: The main difference is that Kalshi charges per-contract trading fees for both sides of a binary, with fees varying by price. Polymarket’s fee model may apply differently to each leg and can include varying rebates or penalties. Always check the latest API responses or market pages for current fee details.
Do fees affect end-of-day edge calculations in KalshiArb?: Yes. When you calculate edge, you must subtract all applicable fees from the raw price-based edge. Since Kalshi settles in USD and prices are in cents, even small fee fractions can affect whether a spread remains profitable after fills.
Is there a guaranteed edge if YES + NO prices sum to less than $1?: An edge can exist if YES_ask + NO_ask is less than $1 after accounting for fees, but there is no risk-free guarantee. Fees, slippage, and resolution timing can erode profits. Treat it as a defined edge rather than a guaranteed payout.
Can I rely on polymarket as a substitute for Kalshi for arbitrage?: Polymarket operates on a different, crypto-backed model and settlement, so it’s not a direct substitute for Kalshi’s USD-regulated market. If your goal is a US-regulated venue with a specific edge profile, KalshiArb focuses on Kalshi-based arbitrage while keeping cross-platform comparisons as context.

How polymarket fees vs kalshi differ in structure

Edge impact on YES/NO price pairs

Practical considerations for arbitrage setups

Start exploiting the Kalshi edge now

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