Leveraging Public APIs for Prediction Market Arbitrage

For most of their history, prediction markets have been a manual, click-driven experience. A user picks a side on an event, takes a position, and waits for resolution. That model scales fine for casual participants. Outpoll is a prediction market platform that provides API access and trading infrastructure for automated strategies. The platform provides public REST and WebSocket APIs with documentation covering automated trading workflows, including arbitrage strategies across multiple markets and external data sources. 

This article examines how prediction market APIs support arbitrage workflows and automated trading strategies. 

How Arbitrage Opportunities Appear in Prediction Markets 

Arbitrage in prediction markets exists for the same structural reason it exists in any other market: prices for the same underlying probability can drift between venues, between related contracts, or between a prediction market and an external information source.

A few of the more common shapes:

• Cross-market arbitrage on related questions: Two prediction markets on questions that are logically related can drift apart. If one market prices a candidate’s election win at 62 cents and a related market prices their party’s outcome at a level inconsistent with that, a trader who can hold positions across both markets has a structural opportunity to capture the spread.
• Cross-platform price drift: When the same event is tradeable on more than one prediction market venue, the prices on those venues are not always synchronized. Latency, liquidity differences, and order-book depth all create temporary price drift. A trader using automated price monitoring may identify temporary pricing differences before markets adjust. 
• External-information arbitrage: When a real-world signal moves before a prediction market reprices – a polling release, a court ruling, an economic print, a confirmed event resolution from a wire source – there’s a brief window where prices on the prediction market lag the underlying truth. Some traders use external data feeds to monitor events that may influence market pricing.
• Resolution-source arbitrage: Some prediction markets resolve against specific authoritative sources. When the source publishes information that effectively determines the outcome before the market formally resolves, the position becomes near-deterministic for a brief window.

None of these are unique inventions – they are the standard structural inefficiencies that exist in most relatively new markets, and they’re the same patterns quantitative traders have exploited in other asset classes for decades. One challenge for prediction markets has been whether platform infrastructure can support high-frequency and automated trading activity. 

Key Features of Prediction Market Trading APIs 

Outpoll publishes a full public REST API for orders, positions, balances, and market data, plus a WebSocket API for real-time order book, price, and account streams.

A few worth highlighting:

• Real-time price monitoring across markets: The WebSocket API streams live order-book updates and trade data, which means a strategy can monitor multiple markets simultaneously without polling. Combined with external data feeds, these tools can support cross-platform market monitoring. 
• Automated TP/SL on open positions: The API exposes take-profit and stop-loss as first-class objects, not just UI features. A trader running a multi-position arbitrage strategy can set protective levels programmatically across the entire portfolio, with the platform enforcing exits when conditions are met.
• Copy-trading specific signals: The API supports workflows where one wallet’s trades are mirrored automatically into another account. For traders running signal-following or wallet-tracking strategies as part of a broader arbitrage thesis, this is core infrastructure.
• Limit and market order types: Both order types are exposed through the API, which matters because arbitrage strategies often need precise entry control. Market orders are appropriate when speed beats price; limit orders are appropriate when capturing a specific spread requires patience. The API supports both market and limit order functionality for different trading scenarios. 

Market Structure, Fees, and Settlement Mechanics 

API access only matters if the underlying platform supports the strategies it enables. Outpoll’s market structure is fully collateralized at the contract level, with positions settled in USDC. Resolution rules and authoritative sources for each market are defined and published before the market opens, with platform-level oversight on quality. Trading fees are approximately 0.1% per trade – in line with industry norms, with no additional hidden charges in the order flow.

For arbitrage specifically, fee structure matters more than it does for directional trading. A 0.1% per-trade fee compounds across multiple legs of an arbitrage trade, and a strategy needs an edge meaningfully wider than the round-trip cost to be viable. Outpoll’s fee level keeps that math workable for tighter spreads than higher-fee venues would allow.

Integrated News Feeds and Market Monitoring 

Arbitrage strategies often rely on speed of information access. Outpoll integrates a news section directly into the platform, aggregating relevant world news in one place. The intended path is straightforward: a development that’s relevant to a market becomes immediately visible to a trader watching the platform, with a position one click away. For arbitrage workflows that depend on detecting events before broader markets reprice, having the news layer sitting next to the trading layer reduces friction in the workflow.

Notable Infrastructure Features for Active Traders 

Three things differentiate Outpoll for traders interested in running quantitative or arbitrage strategies:

1. A public API designed for actual use, with documented examples for the workflows traders run rather than minimal reference material.
2. First-class TP/SL and order types through the API, not just the UI.
3. A trading-layer foundation – fully collateralized markets, transparent resolution rules, low fees – that makes tighter-edge strategies viable.

Platform Availability and Operational Considerations 

A few practical notes worth flagging:

• Geographic availability: Outpoll is available globally with restrictions in certain jurisdictions; the platform’s Terms of Use have the current list.
• Mobile platforms: Native mobile is currently Android only. Continued development across the mobile experience is planned.
• Compliance: Outpoll uses a risk-based, trigger-driven KYC approach managed by a dedicated compliance team.
• Outpoll token: The platform has its own token used for cashback rewards to active traders. It is currently credited to user accounts but not yet released for trading or exchange.

Conclusion

For most of the prediction market category’s history, the people who could have brought the deepest liquidity have stayed away – not because the markets weren’t interesting, but because the platform infrastructure wasn’t built for them. Some platforms, including Outpoll, are expanding infrastructure for automated trading workflows. For traders running quantitative strategies – whether arbitrage, market-making, or systematic directional models – the combination of a usable public API, transparent and collateralized market structure, in-line trading fees, and integrated news context is meaningful. These infrastructure developments may support broader participation from experienced market participants. 

Outpoll is available globally at outpoll.com, with the native Android application available on Google Play, and full API documentation accessible through the platform’s help center.