How to play prediction markets? Four major platforms tested—order book and automated market making each have their own quirks

From problem definition to fund settlement, the “rules of the game” of event contracts are actually hidden in the details. By testing the quoting mechanisms, settlement processes, and fee structures of four major platforms—Polymarket, Kalshi, Robinhood, and TurboFlow—this guide shows the differences between the order book model and the automated market maker model. This article is originally written by MetaHub Research and compiled and translated by PANews.
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Table of contents

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• What is an event contract?
• How do event contracts work?
• Pricing method: What does 70 cents represent?
• Which details should you look at in the settlement rules?
• Platform product reviews
• Polymarket: event markets with continuous trading
• Kalshi: standardized yes/no event contracts
• Robinhood: access partner exchanges through a familiar interface
• TurboFlow: an on-chain trading ecosystem for retail users
• Key differences
• Main risks
• Summary

Event contracts are becoming a new way of playing that’s being discussed in both the crypto space and traditional finance. Put simply: “Get it right by guessing with price.” Buy a contract and bet on the outcome of a question—if you’re right, you get paid; if you’re wrong, it goes to zero. From the long-established prediction market Polymarket, to the standardized contract platform Kalshi, to Robinhood just stepping into this space, and then to TurboFlow—an on-chain platform built around 30-second fast settlement—these four platforms each have their own tricks. A “Dong” team member will take you from rule design to real experience, helping you understand how event contracts work in one go.

What is an event contract?

An event contract throws a verifiable question into the market and sets, in advance, the outcome choices and settlement conditions. Common structures include:

• Yes/No: for example, whether “a certain metric reaches a target before a specified date.”
• Higher/Lower: determining whether the settlement price at expiration is higher or lower than the entry price.
• Threshold-based: determining whether the final value is above, below, or not below a certain value.
• Multi-outcome: the same event defines multiple mutually exclusive outcomes, and each outcome is quoted separately.

Participants trade the contract outcomes. Contract terms typically specify the market question, cutoff time, time zone, official data source, boundary values, how to handle cancelation or postponement events, and the payout amount for winning contracts. Even markets with similar titles may adopt different rules.

How do event contracts work?

• 1. Create a market: the platform defines the question, outcomes, trading cutoff time, and settlement source.
• 2. Form quotes: on order-book platforms, both buyers and sellers place quotes; products using an automated market making mechanism form quotes through a market-making model, and before confirmation they display the participation amount and return information.
• 3. Build positions: after the order is filled, participants hold a position in a particular direction (outcome). Some platforms allow selling before the market closes; whether a sale goes through depends on liquidity.
• 4. Stop trading: after reaching the cutoff time, the event start, or other platform-defined conditions, the market stops accepting trades.
• 5. Confirm the result: the platform, exchange, or a pre-designated oracle confirms the result based on the contract terms and data source.
• 6. Complete settlement: binary contracts typically settle the winning side at $1 per contract and return zero for the losing side; fixed payout products calculate payouts according to the locked rules at the time of confirmation.

Pricing method: What does 70 cents represent?

In binary contracts quoted between 0 and 1 USD, the price is often understood as the market-implied probability. If the “Yes” contract price is $0.70, it roughly corresponds to a 70% probability of occurrence under the current market pricing.

If the final outcome is “Yes,” each contract typically pays $1, so the gross profit (before fees and spreads) is $0.30. If the outcome is “No,” the contract value goes to zero, and the maximum loss is $0.70—the amount invested. Prices are influenced by new information, order book depth, bid-ask spreads, and participants’ supply and demand. The page showing 70% only reflects the market price at that moment and cannot guarantee that the event’s true probability is actually 70%. For fixed payout products that use an automated market making mechanism, the quote also combines cycle, volatility, and risk parameters to form the quote and displays the return rate; participants should check principal, expected return, and the maximum possible loss at the same time.

Which details should you look at in the settlement rules?

• Settlement data source: government agencies, event organizers, price indices, exchange data, or oracles could all become the final basis.
• Comparison symbols: “Higher than 100” usually requires strictly greater than 100; “100 or above” includes 100.
• Time and time zone: which timestamp the settlement uses, which time zone, and whether the sampled price is an instantaneous value, a closing value, or an average over a period.
• Handling exceptions: what happens if the event is postponed, canceled, data is corrected, the price source is interrupted, or the result cannot be determined for a long time.
• Dispute process: who can submit a result, how long the objection period is, and who makes the final decision.
• Fees and payouts: trading fees, platform commissions, on-chain fees, and withdrawal costs all affect the actual return.

Platform product reviews

Polymarket: event markets with continuous trading

Polymarket is a prediction market centered on continuously trading event probabilities. It forms prices through an order book and uses the UMA oracle to participate in confirming results.

• Specific products: mainly shares tied to Yes/No outcomes. Markets cover categories such as politics, macroeconomics, sports, crypto assets, and cultural events; markets typically run until the event occurs and settlement is completed.
• Quotes: uses an order book. The page’s probability typically shows the midpoint between the buy price and the sell price. When the bid-ask spread exceeds $0.10, the page switches to the most recent trade price. The matched quotes for “Yes” plus “No” sum to $1.
• Trading and exit: when the market is open and counterparties exist, you can buy or sell outcome shares through the order book. Limit orders allow you to control the execution price; if liquidity is insufficient, you may not be able to exit at the expected price.
• Settlement: according to the settlement rules published in advance for the market, handled by UMA’s optimistic oracle. After a result is proposed, there is a challenge period. Ultimately, the winning shares pay $1 per contract, while losing shares settle to zero.
• Fees: the official currently states that in some markets, fees are charged to the taker (the order that takes liquidity), while makers (the limit order provider) are not charged. Different market category parameters vary; you must check the latest fee rates before entering.

Review: Suitable for users who want to continuously trade event probabilities, use limit orders, and pay attention to market depth. The key checks are the wording of the rules, bid-ask spreads, on-chain wallets, the oracle dispute process, and regional availability.

Kalshi: standardized yes/no event contracts

Kalshi is an event market centered on standardized yes/no contracts, clear market rules, and order book trading.

• Specific products: mainly yes/no contracts and threshold contracts. In each single market, it lists a clear rules summary, expiration conditions, and outcome verification sources.
• Quotes: uses an order book, with contract prices shown in cents. The 70-cent “Yes” contract and the 30-cent “No” contract together make $1. The best bid, best ask, and tradable quantity directly affect execution.
• Trading and exit: you can use the order book to build positions, and exit by selling when the market is still open and liquidity exists. If your order is left as a resting order and not filled, you can cancel it.
• Settlement: each contract’s terms specify the information and sources used. After the contract expires, Kalshi confirms the result based on those terms. The official explanation says that settlement confirmation may be completed from one hour to twelve hours or more after the market closes, depending on the data source.
• Fees: trading fees are calculated based on factors such as expected returns; some markets may also charge resting-order (maker) fees. Canceling unfilled orders is free—before confirming an order, you should check the actual fees shown on the market page.

Review: Product terms and verification sources are presented more clearly, making it suitable for users who value standardized rules, the order book, and the ability to exit early. The fee formula, market liquidity, and local eligibility need to be verified separately.

Robinhood: access partner exchanges through a familiar interface

Robinhood is an event contract entry point that accesses partner exchanges through a familiar interface; the actual quotes, settlement, and special rules are determined by the exchange that hosts the contracts.

• Specific products: Robinhood’s derivatives business offers event contracts through KalshiEX, ForecastEX, or Rothera Exchange and Clearing. Common formats include single yes/no, threshold contracts, and combined outcome setups.
• Quotes and payouts: the per-contract price is typically between $0.01 and $0.99. Correct outcomes are settled in cash at $1, while incorrect outcomes are settled in cash at $0. Before placing an order, the page shows the price and applicable fees.
• Trading and exit: unfilled orders can be canceled; once filled, they cannot be withdrawn. If the market is still open and there are buyers, you can sell your position at the current market price. If the market closes or liquidity is lacking, you need to hold until settlement.
• Settlement: the final result is determined by the corresponding partner exchange based on the official data sources and terms specified in the contract. Robinhood cannot change the exchange’s settlement decision.
• Fees: may involve both exchange fees and Robinhood commissions; the exact amounts are shown on the order confirmation page.

Review: Suitable for users who already use Robinhood and value a unified operating interface. When reading the terms, you need to confirm which specific exchange actually hosts the contract, because settlement, fees, and special event rule handling are determined by the specific contract.

TurboFlow: an on-chain trading ecosystem for retail users

TurboFlow is an on-chain trading ecosystem aimed at retail users worldwide, combining prediction markets with perpetual contracts. On the same platform, it offers perpetual contracts, event contracts, and prediction markets, using transparent execution and professional liquidity to lower the participation barrier for ordinary users.

• Specific products: this section reviews TurboFlow’s event contracts, i.e., “Higher/Lower” contracts within a fixed time window. Users choose the market, participation amount, cycle, and direction. The minimum participation amount is $2, and a round can be completed in as fast as 30 seconds; the actual parameters are subject to the product page.
• Quotes and participation: an automated market maker (propAMM) forms quotes based on the market, cycle, and risk parameters. Before confirmation, it displays the entry price, participation amount, cycle, direction, return rate, and the anticipated outcome; after the order is confirmed, the return rate for that contract is locked.
• Settlement: the entry price is the price when the order is accepted, and the settlement price is the price used when the contract expires. If you choose “Higher,” the settlement price must be higher than the entry price to match the direction; if you choose “Lower,” it’s the opposite. If the two are the same, principal is returned according to the official rules.
• Position management: after the countdown ends, it settles automatically. During the holding period, there’s no need to manage margin, funding rates, or forced liquidation; this mechanism differs from TurboFlow’s perpetual contract products.

Review: TurboFlow targets retail users by lowering the participation threshold for event contracts to a minimum of $2 and a fastest completion time of 30 seconds, and it integrates perpetual contracts and prediction markets on the same platform. Short-cycle “Higher/Lower” contracts are more sensitive to entry timing, market volatility, and price data.

Key differences

• Price formation: Polymarket and Kalshi mainly rely on the order book; Robinhood displays the partner exchange’s market quotes; TurboFlow event contracts use an automated market maker (propAMM) to form quotes, and before confirmation they show the entry price, participation amount, cycle, direction, and the locked return rate.
• Time span: Polymarket, Kalshi, and Robinhood contracts usually operate around the event cutoff time; TurboFlow event contracts use a fixed time window, completing a round in as fast as 30 seconds.
• Early exit: for the first three product types, you can usually sell your position when the market is open and liquidity exists; TurboFlow’s public process focuses on holding until the countdown ends and then settling automatically.
• Settlement counterparty: Polymarket uses the UMA oracle; Kalshi confirms based on its own market terms and specified sources; Robinhood is determined by the partner exchange; TurboFlow event contracts settle automatically based on pre-disclosed contract rules—using entry and settlement prices generated from credible market data sources and multiple oracles.
• Applicable scenarios: if you care about continuously changing event probabilities, focus on Polymarket; if you prioritize standardized market rules, study Kalshi; if you prefer Robinhood’s unified interface, check its partner-exchange-hosted contracts; if you want to participate with a low threshold in short-cycle “Higher/Lower” contracts, consider TurboFlow event contracts.

Main risks

• Principal loss: if your direction judgment is wrong, a per-contract position may go to zero; fixed payout products may also lose the participation amount.
• Rule risk: ignoring boundary values, time zones, data sources, or abnormal clauses may lead to incorrect expectations about the settlement outcome.
• Liquidity and spreads: the displayed probabilities, executable prices, and early-exit prices may differ noticeably.
• Settlement and data risks: delayed official data, corrections, oracle disputes, or abnormal price sources may extend settlement and trigger special rules.
• Fee risk: trading fees, commissions, on-chain network fees, and deposit/withdrawal fees reduce the actual return.
• Technical and compliance risk: account security, smart contracts, platform operations, and regional restrictions can all affect product availability.

Summary

To understand event contracts, you can review them across five steps: “problem definition—price formation—trading exit—result confirmation—fund settlement.” Polymarket, Kalshi, Robinhood, and TurboFlow event contracts follow different product paths. Among them, TurboFlow itself is an on-chain trading ecosystem that combines prediction markets and perpetual contracts—this article’s review covers only its event contract product. Platform names cannot replace verifying a single contract’s terms. What truly determines the outcome is the time, data sources, boundary conditions, and exception-handling rules written into the contract.