How are Polymarket trading fees calculated?

Fees are calculated as shares multiplied by 0.072, multiplied by the price, multiplied by one minus the price. This structure maximizes fees when probabilities are close to 50%.

What is the difference between maker and taker fees on Polymarket?

Makers pay zero fees, while takers pay significantly more. The fee structure penalizes takers who trade near the coin flip range.

Can retail traders profit from Polymarket arbitrage?

Simple arbitrage opportunities only last two to three seconds before automated bots take them. Complex arbitrage between linked markets exists but suffers from low liquidity, limiting actual profit.

What risks do users face on Polymarket?

Users report losses from oracle manipulation where large wallets control voting outcomes. Other risks include a lack of regulation, poor customer support, and competing against professional high frequency trading bots.

Polymarket Fees Spreads and Arbitrage Explained

Polymarket charges higher taker fees and zero maker fees, with costs peaking when market probabilities sit near 50/50. The fee formula uses shares, price, and the inverse of the price, making frequent trading near a coin flip the most expensive approach.

Spread and slippage eat into profitability. Even slight execution delays or stale quotes lead to adverse selection, meaning the actual fill price is often worse than expected.

Simple arbitrage opportunities disappear in seconds because automated bots grab them. Complex arbitrage across linked markets offers more potential but lacks the liquidity needed for large profits.

Polymarket Fees Spreads and Arbitrage Explained — infographic

On Polymarket, fees and spreads significantly impact profitability, with taker fees being notably higher than maker fees, and arbitrage opportunities often quickly exploited by bots. Be aware that while maker orders can avoid direct fees, market spreads and the speed of execution remain crucial challenges.

Understanding Polymarket Fees

Taker Fees vs. Maker Fees: Polymarket charges a fee on every trade, with takers generally paying significantly more. "Makers pay zero." The fee structure is designed such that "the fee is worst exactly where most people trade (near the coin-flip)."

Fee Calculation: The fee is calculated as shares × 0.072 × price × (1 − price). This means that when a market's probability is near 50/50, the fee is maximized.

Comparison to Competitors: Some users claim Polymarket's fees can be "up to 250x higher than competitors" for certain markets, though others argue that while competitor fees might be lower, their spreads are often higher, potentially negating the benefit.

Navigating Spreads and Slippage

Impact of Spreads: The difference between the buy and sell price (the spread) can significantly affect profitability, especially for small trades. "The closer the odds are, the higher the fees on Polymarket (ps. be a maker!!)"

Slippage: Even with a profitable strategy in theory, "execution realism" reveals that "edge dies with ~0.01 additional slippage." This means the price you expect to get may not be the price you actually receive.

Quote Freshness: Stale quotes can lead to "adverse selection," where you fill an order at a disadvantageous price because others have faster information. "conditions * bearish/DOWN setups * tighter spread environments Biggest engineering lesson so far as well as delusional elements was prediction latency wasn’t the bottleneck at all. Inference: ~100ms While the actual bottleneck was these all along-"

Arbitrage Opportunities

Fast Bots Exploit Simple Arbs: Simple arbitrage opportunities, like buying YES and NO shares when their combined price is less than $1, are quickly exploited by bots. "The simple arb is basically dead if you're retail anyway, windows are like 2-3 seconds and the fast bots eat it before you'd even notice it was there."

Complex Arbitrage: More complex arbitrage involves "linked markets" (e.g., "Trump wins" vs. "a Republican wins") which can be more challenging to track and often involve longer resolution times. "but the part i hadn't seen anywhere is that only like 10 of that is the simple yes+no under a dollar arb everyone already knows about. the other ~29 mil is the stuff between linked"

Liquidity Limitations: Even when arbitrage opportunities exist between platforms like Polymarket and Kalshi, "the arb ops lack the liquidity to be very profitable."

Challenges and Risks

Oracle Manipulation: Users have reported significant losses due to alleged oracle manipulation, where "whale wallets control over half of the entire protocol's voting power" and can collude to force a specific outcome.

Lack of Regulation and Customer Service: Some users express concerns about Polymarket's regulatory status and lack of customer support. "Thousands of $$ stolen from me and countless others and also can't withdraw my remaining funds."

High-Frequency Trading: Competing with professional traders and bots requires sophisticated tools and infrastructure. "You cannot compete with sharp money by clicking around the Polymarket website, waiting for the UI to load."

Are you considering using Polymarket for trading?