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

What is an Event Contract?

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

• Yes/No: For example, "Will a specific indicator reach a target by a specified date?"
• Higher/Lower: Determines if the settlement price is higher or lower than the entry price.
• Threshold: Determines if the final value is above, below, or not below a certain number.
• Multi-Outcome: Multiple mutually exclusive outcomes are set for the same event, each with its own price.

Participants trade on the outcome of the contract. The contract terms typically specify the market question, deadline, time zone, official data source, boundary values, handling of canceled or postponed events, and the payout amount for the winning contract. Markets with similar titles may also 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 are quoted by buyers and sellers; on products using automated market makers, prices are formed by the market-making model, showing the participation amount and return information before confirmation.
• 3. Position Establishment: After the order is filled, the participant holds a position in a specific outcome direction. 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 pre-designated oracle confirms the result based on the contract terms and data source.
• 6. Settlement Completion: Binary contracts typically settle the winning side at $1 per share and the losing side at $0; fixed-return products are calculated based on the rules locked at the time of confirmation.

Pricing: What Does 70 Cents Represent?

In binary contracts priced between $0 and $1, the price is often interpreted as the market-implied probability. A "Yes" contract price of $0.70 indicates that the current market pricing roughly corresponds to a 70% probability of occurrence.

If the final outcome is "Yes", each contract 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 goes to zero, and the maximum loss is the invested $0.70.

The price is affected by new information, order book depth, bid-ask spread, and participant supply and demand. A displayed 70% only reflects the market price at that time and does not guarantee the event's true probability is 70%. Fixed-return products using automated market-making mechanisms also incorporate cycle time, volatility, and risk parameters to form a price and display the return rate; participants should simultaneously review the principal, expected return, and maximum possible loss.

What Settlement Rules Details to Check?

• Settlement Data Source: Government agencies, event organizers, price indices, exchange data, or oracles can all serve as the final basis.
• Comparison Symbol: "Above 100" typically requires a value strictly greater than 100; "100 or above" includes values equal to 100.
• Time and Timezone: Which point in time 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 to handle event postponements, cancellations, data corrections, price feed interruptions, or situations where the outcome cannot be determined for an extended period.
• Dispute Process: Who can challenge the result, the length of the objection period, and who makes the final decision.
• Fees and Payouts: Transaction fees, platform commissions, on-chain gas fees, and withdrawal costs all affect the actual return.

Platform Product Review

Polymarket: Continuously Traded Event Market

Polymarket is a prediction market for continuously trading event probabilities, forming prices via an order book, with the UMA oracle involved in outcome confirmation.

• Specific Products: Primarily Yes/No outcome shares, covering categories like politics, macroeconomics, sports, crypto assets, and cultural events. Markets typically remain active until the event occurs and are settled.
• Quotes: Order book based. The displayed probability is usually the midpoint between the best bid and best ask. When the bid-ask spread exceeds $0.10, the page switches to the last traded price. The combined price for "Yes" and "No" shares equals $1.
• Trading and Exit: While the market is open and a counterparty exists, outcome shares can be bought or sold via the order book. Limit orders allow control over the execution price; exiting at the desired price may not be possible if liquidity is insufficient.
• Settlement: Handled by the UMA optimistic oracle according to the pre-announced market rules. A challenge period follows the outcome proposal; winning shares settle at $1 each, losing shares at $0.
• Fees: Current official guidelines state that fees are charged to the taker in some markets, while makers are not charged. Parameters vary by market category; check the latest fee schedule before entering.

Review: Suitable for users who want to continuously trade event probabilities, use limit orders, and pay attention to market depth. Key items to check are the wording of rules, bid-ask spread, on-chain wallet requirements, oracle dispute process, and regional availability.

Official Resources: 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 clear rule summaries, expiration conditions, and outcome verification sources.
• Quotes: Order book based. Contract prices are expressed in cents. A "Yes" contract at 70 cents and a "No" contract at 30 cents combine to $1. The best bid, best ask, and available quantities directly affect execution.
• Trading and Exit: Positions can be opened using the order book and exited via sell orders while the market is open and has liquidity. Unfilled orders can be cancelled.
• Settlement: Each contract's terms specify the information and sources used. After expiration, Kalshi confirms the result based on these terms. Official guidelines state that settlement confirmation may be completed between one hour to over twelve hours after market close, depending on the data source.
• Fees: Transaction fees are calculated based on factors like expected profit. Some markets may also charge maker fees. Cancelling an unfilled order is free; check the actual fees displayed on the market page before confirming an order.

Review: Product terms and verification sources are relatively clearly displayed. Suitable for users who value standardized rules, order books, and the ability to exit early. The fee formula, market liquidity, and regional eligibility need to be checked individually.

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

Robinhood: Accessing Partner Exchanges via a Familiar Interface

Robinhood is an entry point for event contracts via a familiar interface, connecting to partner exchanges. The actual quotes, 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 combination outcomes.
• Quotes and Payouts: Single share prices typically range between $0.01 and $0.99. Correct outcomes settle in cash at $1 per share; incorrect outcomes settle at $0. Price and applicable fees are displayed before placing an order.
• Trading and Exit: Unfilled orders can be cancelled. Filled orders cannot be reversed. While the market is still open and has a buyer, positions can be sold at the current market price. If the market is closed or lacks liquidity, positions must be held until settlement.
• Settlement: The final outcome is determined by the respective partner exchange based on the official data sources and terms specified 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 who already use Robinhood and value a unified operational interface. When reading the terms, it is necessary to identify the exchange that actually hosts the contract, as settlement, fees, and special event rules are determined by that specific contract.

• Official Resources: Robinhood Operational Rules｜Robinhood Exit Rules

TurboFlow: 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 the same platform, lowering the entry barrier for ordinary users through transparent execution and professional liquidity.

• Specific Products: This section reviews TurboFlow's Event Contracts, specifically "Higher/Lower" contracts with a fixed time frame. Users select the market, participation amount, duration, and direction. The minimum participation amount is $2, with rounds potentially completing in as fast as 30 seconds. Real-time parameters are subject to the product page.
• Quotes and Participation: An automated market maker (propAMM) forms the quote based on market, duration, and risk parameters. Before confirmation, the entry price, participation amount, duration, direction, return rate, and projected outcome are displayed. The return rate is locked once the order is confirmed.
• Settlement: The entry price is the price at which the order is accepted; the settlement price is the price used at contract expiration. If "Higher" is chosen, the settlement price must be higher than the entry price to be in the money; the opposite is true for "Lower". If they are equal, the principal is returned according to the official rules.
• Position Management: Positions settle automatically after the countdown ends. No margin maintenance, funding rates, or forced liquidation are required during the holding period. This mechanism differs from the platform's perpetual contract products.
• Official Resources: TurboFlow Event Contracts

Review: TurboFlow targets retail traders, lowering the entry barrier for event contracts with a minimum of $2 and rounds as fast as 30 seconds, integrating 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.

Key Differences

• Price Formation: Polymarket and Kalshi primarily rely on order books; Robinhood displays market quotes from partner exchanges; TurboFlow Event Contracts use an automated market maker (propAMM) to form quotes, displaying entry price, participation amount, duration, direction, and locked return rate before confirmation.
• Time Horizon: Polymarket, Kalshi, and Robinhood contracts typically run until the event deadline; TurboFlow Event Contracts use a fixed time frame, with rounds potentially completing in as fast as 30 seconds.
• Early Exit: The first three types of products usually allow selling positions while the market is open and has liquidity; the standard flow for TurboFlow Event Contracts involves holding until the countdown ends and settling automatically.
• Settlement Entity: Polymarket uses the UMA oracle; Kalshi confirms results based on its own market terms and designated sources; Robinhood's outcome is determined by the partner exchange; TurboFlow Event Contracts settle automatically based on pre-disclosed contract rules, using trusted market data sources and entry/settlement prices generated by multiple oracles.
• Use Cases: Users focused on continuously changing event probabilities can research Polymarket; those valuing standardized market rules can research Kalshi; users preferring Robinhood's unified interface can review its partner exchange contracts; those seeking low-barrier participation in short-duration "Higher/Lower" contracts can research TurboFlow Event Contracts.

Key Risks

• Principal Loss: If the direction is judged incorrectly, a single contract can become worthless, and fixed-return products may also result in the loss of the participation amount.
• Rule Risk: Ignoring boundary values, time zones, data sources, or exception clauses can lead to incorrect expectations for the settlement result.
• Liquidity and Spread: The displayed probability, fillable price, and early exit price may differ significantly.
• Settlement and Data Risk: Official data delays, corrections, oracle disputes, or price feed anomalies can extend settlement and trigger special rules.
• Fee Risk: Transaction fees, commissions, on-chain network fees, and deposit/withdrawal costs reduce the actual return.
• Technical and Compliance Risk: Account security, smart contract risks, platform operations, and regional restrictions can all affect product usability.

Summary

Understanding event contracts can be approached by checking five key stages: "Problem Definition – Price Formation – Trading/Exit – Outcome Confirmation – Fund Settlement." Polymarket, Kalshi, Robinhood, and TurboFlow Event Contracts adopt different product paths; TurboFlow itself is an on-chain trading ecosystem integrating prediction markets and perpetual contracts, with this article reviewing only its event contract product. The platform name cannot substitute for checking the terms of an individual contract. What truly determines the outcome are the time, data sources, boundary conditions, and exception handling rules specified in the contract.