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Overview

What is Gameday?​

Gameday is a Web3-powered sports betting exchange that is currently operating on Optimism network to leverage low transaction fees and fast finality. It combines the efficiency of a central limit order book (CLOB) for real-time market making with the transparency and security of on-chain settlement.

Unlike traditional sporstbooks, Gameday exchange does not set odds or take the other side of your bet. Instead, it provides a peer-to-peer marketplace where participants trade binary contracts representing the outcome of sporting events. Every matched position is settled on-chain, ensuring results are verifiable, trust-minimized, and resistant to tampering.

Core Concepts​

Binary Contracts​

Binary contracts are a fundamental building block of our betting exchange, allowing you to bet on the outcome of future events in a clear and straightforward way. A binary contract is a simple financial instrument that represents the outcome of an event with only two possibilities: "YES" or "NO". For example:

  • Will Team A win the match?

If you believe Team A will win, you buy "YES" contracts, but if you believe Team A will not win, you buy "NO" contracts (which is the same as selling "YES" contracts).

Pricing

Contracts are priced from $0 to $1, for example:

  • If you buy 1 "YES" at a price of $0.65 (which implies there's approx. 65% chance the outcome will occur), and Team A wins, you receive a total of $1: $0.65 stake and $0.35 reward.
  • On the other hand, if selected outcome does not occur, you receive nothing.

Unlike traditional betting where you can only place a wager and wait, binary contracts can be bought and sold anytime on our exchange. You can trade these contracts just like you would stocks or other assets. For example, you can sell contracts you already own to lock in profits or cut losses before the event concludes. If you bought a "YES" contract for $0.70 and its price rises to $0.85, you can sell it to someone else and pocket the $0.15 profit per contract.

Central Limit Order Book​

Trading takes place via orderbook, where participants can post limit orders or take existing offers. It is a real-time transparent system where users can see market depth at each price level. Matched orders are executed on price-time priority, where the first order at a given price is executed first.

This ensures:

  • Transparent order matching: all outstanding offers are visible to participants.

  • Fair price discovery: orders are matched based on price-time priority.

On-Chain Settlement​

While the order book engine is off-chain, order execution, settlement of positions and payouts is handled on a public blockchain.

Settlement

Blockchain settlement ensures:

  • Custody in your control: funds are secured in blockchain wallets, not held by the exchange.
  • Immutable records: every trade, payout and market resolution is recorded on the blockchain, which means results are permanent and cannot be altered.
  • Provable results: settlement logic is verifiable via smart contracts.

Permissionless Participation​

Any wallet with Optimism access (eg. Metamask) can connect and trade. No account registrations or onboarding processes - once connected, traders can place orders immediately.

Safe Wallet Practices

  • Always keep control of your wallet and private keys. Never share or enter your seed phrase or private key into any website, app, or bot.

  • Consider using a hardware wallet for added security.

  • Only approve transactions from contracts and dApps you trust, and double-check the details before confirming.

  • Regularly review your wallet’s approvals to revoke access you no longer need.

Remember: you are solely responsible for the safety of your funds.

Messaging flow​