Please describe your proposed solution
Prediction markets are a powerful tool for accurate crowd-sourced forecasting, yet Cardano lacks the infrastructure to support them, unlike other blockchains like Polygon, which hosts Polymarket, a prominent prediction market. We propose developing open-source prediction market smart contract templates for Cardano, enabling users to create fully decentralised prediction markets tailored to their needs.
These contracts will be initialized by specifying parameters like name, description, deadline, and outcomes. Users provide liquidity to mint "outcome tokens," representing different scenarios, which can be traded on the open market.
Once the contract is created, users can provide liquidity to the prediction market until the deadline passes.
After the deadline for a market passes, the market can be settled either by a trusted party or an oracle. We leave the settlement as an implementation detail now, as we want our contracts to support arbitrary settlement mechanisms.
After settlement, users can provide their outcome tokens to the contract to be burned in exchange for ADA for each outcome token corresponding to the settled outcome. For example if a user owns 75 tokens for outcome A and 25 for outcome B with outcome A being the settled outcome, each of their outcome A tokens are worth 1 ADA and each of their outcome B tokens are worth 0 ADA.
Providing liquidity mints an equal amount of "outcome tokens" representing the belief in a given outcome to the liquidity provider. For example, for a binary prediction market, if a user were to provide 100 ADA of liquidity they would receive 100 tokens for outcome A and 100 tokens for outcome B.
These tokens essentially represent a 50% chance for either outcome occurring. These tokens can then be further traded on the open market. Users that wish to make a prediction can simply buy outcome tokens for a single outcome instead of providing liquidity and receiving both outcome tokens. The price of the individual outcome tokens is driven by their initial minting price (for binary markets this would be 0.5 ADA for each token) and the market sentiment.
The market sentiment is the key factor that makes prediction markets work. If it costs 0.5 ADA to mint a token for outcome A, but market participants believe that outcome has an 80% chance of happening, then they know they can pay 0.5 ADA to have an 80% chance of getting 1 ADA in the future. This presents an arbitrage opportunity!
Minting equal amounts of both tokens to liquidity providers guarantees the market will always have enough funds to resolve and also accurately represents the outcome probabilities. When token A trades for 0.8 ADA / token on the open market, if the other ticket were to cost more than 0.2 ADA, the liquidity providers would be getting more than 1 ADA for each ADA they provide as liquidity, which is another arbitrage opportunity that will make the token market balance the price out.
The price of individual outcome tokens also won't feasibly rise above 1 ADA, as each token is only collateralised by 1 ADA, meaning if a market participant were to pay 1.1 ADA for it, they would only stand to get 1 ADA in the future, losing 0.1 ADA. Rational market participants wouldn't do this, capping the price to 1 ADA.
Other crypto ecosystems already have existing prediction markets that help users express their opinions, gauge sentiments and motivate their decisions. A chief example of this is Polymarket on the Polygon blockchain. Our proposal stands out by providing the prediction markets as an open source blueprint that can be used by anyone to build a prediction market with whatever settlement mechanism they decide on, be it an oracle, a multisig or something else altogether.
These prediction market contracts are designed to be highly modular and extensible, allowing developers to easily integrate and customise them for a wide range of use cases within the Cardano ecosystem:
- Financial Forecasting
- Speculate on asset prices which enables insights and hedging strategies based on real-time market sentiment for investors and traders.
- Sports Betting
- Bet on sporting events, offering transparency and a trustless environment without relying on centralised platforms.
- Political Predictions
- Forecast election outcomes or policy changes, providing a tool for gauging public sentiment and making data-driven decisions
- Corporate Decision-Making
- Gather insights from stakeholders on crucial business outcomes like product launches or sales performance, for better business decision-making.
- Academic research
- Study collective intelligence, market dynamics, and game theory, providing a solid environment for experimentation and data collection.
- Other Applications
- A variety of other scenarios could make use of the contracts such as technological forecasting and environmental predictions.
Builders in the cardano ecosystem could easily leverage the prediction market contracts when developing without needing to reinvent the wheel. It’s just as simple as dropping these contracts into a codebase and tweaking it to fit their needs. The contracts are highly customizable, whether through defining different settlement mechanisms (oracles or trusted parties), adjusting the number of outcomes, or setting parameters for liquidity provision and token minting. These contracts will enable further innovation on Cardano, empowering developers and builders to quickly build up their solutions.