How to Play Event Contracts? A Comparison of 4 Major Platforms

What is an Event Contract?

An event contract presents a verifiable question, pre-defines outcome options, and settlement conditions. Common structures include:

• Yes/No: For example, "Will a certain indicator reach a target by a specified date?"
• Higher/Lower: Judging whether the expiration price is higher or lower than the entry price.
• Threshold type: Determining if the final value is above, below, or not below a certain number.
• Multiple Outcomes: Setting multiple mutually exclusive outcomes for the same event, each priced separately.

Participants trade the contract's outcome. The contract terms usually list the market question, deadline, timezone, official data source, boundary values, handling of canceled or postponed events, and the payout amount for winning contracts. Markets with similar titles can have different rules.

How Do Event Contracts Work?

• 1. Market Creation: The platform defines the question, outcomes, trading deadline, and settlement source.
• 2. Price Formation: On order book platforms, prices come from buyer and seller quotes. Products using automated market makers have prices formed by the market-making model, showing participation amounts and return information before confirmation.
• 3. Position Establishment: After an order executes, a participant holds a position for a specific outcome. Some platforms allow selling before the market closes, depending on liquidity.
• 4. Trading Halt: The market stops accepting trades upon reaching the deadline, the start of the event, or other conditions specified by the platform.
• 5. Outcome Confirmation: The platform, exchange, or a pre-designated oracle confirms the outcome based on contract terms and data sources.
• 6. Settlement Completion: Binary contracts typically settle winning shares at $1 each, losers at $0; fixed-return products calculate payouts based on rules locked at confirmation.

Pricing: What Does 70 Cents Mean?

In binary contracts priced between $0 and $1, the price is often interpreted as the market's implied probability. A "Yes" contract price of $0.70 suggests the market currently prices in roughly a 70% probability of occurrence.

If the final outcome is "Yes," each share typically pays out $1, resulting in a gross profit of $0.30, excluding fees and spreads. If the outcome is "No," the contract's value becomes zero, with a maximum loss of $0.70 invested.

Prices are influenced by new information, order book depth, bid-ask spreads, and participant supply and demand. A page showing 70% only reflects the market price at that moment and cannot guarantee the true event probability is 70%. Fixed-return products using automated market makers also incorporate duration, volatility, and risk parameters to form prices and display yields. Participants should review the principal, expected return, and maximum possible loss simultaneously.

What Settlement Rules Should You Check?

• Settlement Data Source: Government agencies, event organizers, price indices, exchange data, or oracles can be the final authority.
• Comparison Symbols: "Above 100" typically requires strictly greater than 100; "100 or above" includes 100.
• Time and Timezone: Which time point and timezone are used for settlement, and whether the price sample is an instantaneous value, closing value, or an average over a period.
• Exception Handling: How postponements, cancellations, data corrections, price feed interruptions, or prolonged inability to determine an outcome are handled.
• Dispute Process: Who can challenge the outcome, the objection period, and who makes the final decision.
• Fees and Payouts: Trading fees, platform commissions, on-chain fees, and withdrawal costs all affect actual returns.

Platform Product Review

Polymarket: Continuously Tradable Event Market

Polymarket is a prediction market for continuous trading around event probabilities. It forms prices via an order book and uses the UMA oracle for outcome confirmation.

• Specific Products: Primarily Yes/No outcome shares, covering categories like politics, macroeconomics, sports, crypto assets, and cultural events. Markets typically run until the event occurs and settles.
• Pricing: Uses an order book. The displayed probability is usually the midpoint between the best bid and ask. When the spread exceeds $0.10, the page switches to the last traded price. The matched quotes for "Yes" and "No" sum to $1.
• Trading and Exit: When the market is open and a counterparty exists, outcome shares can be bought or sold via the order book. Limit orders control execution price; exit at the desired price may not be possible if liquidity is insufficient.
• Settlement: Handled by the UMA optimistic oracle according to pre-announced market rules. A challenge period follows the proposed outcome. Winning shares pay out $1 each at settlement; losing shares become worthless.
• Fees: Official documentation currently states fees are charged to the taker for some markets, with makers not paying fees. Parameters vary by market category; check the latest rates before participating.

Review: Suitable for users who want to continuously trade event probabilities, use limit orders, and monitor market depth. Key checks are rule wording, bid-ask spreads, on-chain wallet usage, the oracle's dispute process, and regional availability.

Official Info: Polymarket Pricing Rules | Polymarket Settlement Rules | Polymarket Fee Rules

Kalshi: Standardized Yes/No Event Contracts

Kalshi is an event market centered around standardized Yes/No contracts, clear market rules, and order book trading.

• Specific Products: Primarily Yes/No contracts and threshold contracts. Each market lists a clear summary of rules, expiration conditions, and result verification sources.
• Pricing: Uses an order book; contract prices are in cents. A 70-cent "Yes" contract and a 30-cent "No" contract sum to $1. The best bid, best ask, and available quantities directly affect execution.
• Trading and Exit: Positions can be established via the order book and exited by selling if the market is still open and liquid. Unfilled orders can be canceled.
• Settlement: Each contract's terms specify the information and source used. After expiration, Kalshi confirms the outcome based on these terms. Official documentation states settlement confirmation may be completed between one hour and over twelve hours after market close, depending on the data source.
• Fees: Trading fees are calculated based on factors like expected profit. Some markets may also charge maker fees. Canceling unexecuted limit orders is free; check the actual fees on the market page before confirming an order.

Review: Product terms and verification sources are displayed clearly. Suitable for users who value standardized rules, order books, and the ability to exit early. Fee formulas, market liquidity, and regional eligibility need separate review.

Official Info: Kalshi Pricing Rules | Kalshi Market Rules | Kalshi Fee Rules

Robinhood: Accessing Partner Exchanges via a Familiar Interface

Robinhood is an event contract entry point via a familiar interface, connecting to partner exchanges. The actual pricing, settlement, and special rules are determined by the exchange hosting the contract.

• Specific Products: Robinhood's derivatives business offers event contracts through KalshiEX, ForecastEX, or Rothera Exchange and Clearing. Common forms include single Yes/No, threshold contracts, and combined outcomes.
• Pricing and Payout: Single share prices typically range from $0.01 to $0.99. Correct outcomes settle in cash at $1 per share; incorrect outcomes settle at $0. The price and applicable fees are displayed before placing an order.
• Trading and Exit: Unfilled orders can be canceled. Executed orders cannot be revoked. If the market is still open and there are buyers, positions can be sold at the prevailing market price. If the market is closed or lacks liquidity, positions must be held until settlement.
• Settlement: The final outcome is determined by the corresponding partner exchange based on the official data source and terms stipulated in the contract. Robinhood cannot alter the exchange's settlement decision.
• Fees: May involve both exchange fees and Robinhood commissions. The specific amounts are shown on the order confirmation page.

Review: Suitable for users already on Robinhood who value a unified operating interface. When reading the terms, users need to identify the exchange holding the actual contract, as settlement, fees, and special event rules are governed by that specific contract.

• Official Info: Robinhood Operating Rules | Robinhood Exit Rules

TurboFlow: An On-Chain Trading Ecosystem for Retail Traders

TurboFlow is an on-chain trading ecosystem for global retail traders, integrating prediction markets with perpetual contracts. It offers perpetual contracts, event contracts, and prediction markets on a single platform, aiming to lower entry barriers for ordinary users through transparent execution and professional liquidity.

• Specific Products: This review covers TurboFlow's event contracts, specifically fixed-time-window "Higher/Lower" contracts. Users select a market, participation amount, duration, and direction. The minimum participation amount is $2, and a round can be completed in as fast as 30 seconds. Real-time parameters are subject to the product page.
• Pricing and Participation: An automated market maker (propAMM) forms the price based on market, duration, and risk parameters. Before confirmation, the entry price, participation amount, duration, direction, payout rate, and projected outcome are displayed. Once the order is confirmed, the payout rate for that contract is locked.
• Settlement: The entry price is the price when the order is accepted; the settlement price is the price used at contract expiration. For a "Higher" position, the settlement price must be higher than the entry price to be correct. The opposite applies for a "Lower" position. If they are equal, the principal is returned per official rules.
• Position Management: Positions settle automatically after the countdown ends. No margin management, funding rates, or forced liquidation is required during the holding period. This mechanism differs from the platform's perpetual contract product.

Review: TurboFlow targets retail users, lowering the entry barrier for event contracts with a minimum of $2 and rounds as fast as 30 seconds. It integrates perpetual contracts and prediction markets on the same platform. Short-duration "Higher/Lower" contracts are more sensitive to entry timing, market volatility, and price data.

• Official Info: TurboFlow Event Contracts

Key Differences

• Price Formation: Polymarket and Kalshi primarily rely on order books. Robinhood displays market quotes from partner exchanges. TurboFlow's event contracts use an automated market maker (propAMM) to form prices, displaying entry price, participation amount, duration, direction, and locked payout rate before confirmation.
• Time Horizon: Polymarket, Kalshi, and Robinhood contracts typically run around an event deadline. TurboFlow event contracts use fixed time windows, completing a round in as fast as 30 seconds.
• Early Exit: The first three product types usually allow selling positions if the market is open and liquid. TurboFlow event contracts' public process focuses on holding until the countdown ends for automatic settlement.
• Settlement Entity: Polymarket uses the UMA oracle. Kalshi confirms outcomes based on its own market terms and specified sources. Robinhood's outcome is determined by the partner exchange. TurboFlow event contracts settle automatically based on pre-disclosed rules, using trusted market data sources and entry/settlement prices generated by multiple oracles.
• Use Cases: For those focused on continuously changing event probabilities, research Polymarket. For those valuing standardized market rules, research Kalshi. For those preferring Robinhood's unified interface, review its partner exchange contracts. For those seeking low-barrier participation in short-duration "Higher/Lower" contracts, research TurboFlow's event contracts.

Main Risks

• Principal Loss: Incorrect direction can result in a total loss on the contract. Fixed-return products can also lead to loss of the participation amount.
• Rule Risk: Ignoring boundary values, timezones, data sources, or exceptional clauses can lead to incorrect expectations about the settlement outcome.
• Liquidity and Spreads: The displayed probability, executable price, and early exit price can differ significantly.
• Settlement and Data Risk: Official data delays, corrections, oracle disputes, or price feed anomalies can delay settlement and trigger special rules.
• Fee Risk: Trading fees, commissions, on-chain network fees, and deposit/withdrawal costs reduce actual returns.
• Technical and Compliance Risk: Account security, smart contract risk, platform operations, and regional restrictions can all affect product usability.

Conclusion

To understand event contracts, check the five stages: "Problem Definition – Price Formation – Trade & Exit – Outcome Confirmation – Fund Settlement." Polymarket, Kalshi, Robinhood, and TurboFlow event contracts follow different product paths. TurboFlow itself is an on-chain trading ecosystem integrating prediction markets and perpetual contracts; this review only covers its event contract product. The platform name cannot substitute for reviewing the terms of an individual contract. The outcome is truly determined by the time, data source, boundary conditions, and exception handling rules written in the contract.