4 Arbitrage & Comparison Engines Tools for Prediction Markets

This post is part of a series covering the Prediction Market ecosystem. You can view the full interactive map with more than 60 startups here.

This market map represents the “financialization of information” (Think of Polymarket and Kalshi as the current main exchanges). In this ecosystem, world events are treated like stocks, and the tools below are what traders, developers, and everyday users use to navigate this new economy.

Arbitrage & Comparison Engines for Prediction Markets

What is this category about?

This category is probably the most “niche” one, and I hesitated to just add these tools in the trading tools category. Anyway, this category is dedicated to tools that leverage the mathematical gaps between different markets, ensuring that “Truth” is priced consistently across the entire global landscape.
Cross-Platform Mapping & Price Disparity Tools

The Big Picture: This category is about Price Parity. Because the same event (e.g., “Who will win the 2026 World Cup?”) is traded on multiple different platforms like Polymarket and Kalshi, the prices are often slightly different. These tools scan all available venues simultaneously to find these “gaps,” allowing users to buy an outcome where it is cheap and sell it (or hedge it) where it is expensive.
Role in the Layer System: They sit on top of the APIs tools (Layer 2) to pull real time data from every exchange in Layer 1, presenting the user with a consolidated view of the best possible price for any given “Truth.”

What are the core values provided?

Risk Free Profit (Arbitrage): Automatically identifies “sure-win” scenarios where the combined odds across two platforms allow a trader to bet on all outcomes and still lock in a guaranteed profit.
Best Price Discovery: For the casual user, these tools act like a “Skyscanner” for predictions, showing you exactly which exchange offers the highest payout for your specific belief.
Market Correction: By helping traders exploit price gaps, these tools force different exchanges to align their prices, which improves the overall accuracy of the global “Truth” signal.
Slippage & Fee Calculation: These engines often include “Net Profit” calculators that factor in gas fees, exchange commissions, and liquidity depth, ensuring the arbitrage is actually profitable after costs.

Who are the main user groups?

Professional tarders: Math driven traders who don’t care about the event outcome but only care about the mathematical “spread” between platforms.
Prosumers: Users who want to make sure they aren’t overpaying for a “Yes” share on one platform when it’s 5% cheaper on another.

The “Arbitrage Portfolio” Strategies
Here is the current meta when it comes to arbitrage trading:

The Identical Match: Finding the exact same contract on two exchanges (e.g., Polymarket vs. Kalshi) and exploiting a direct price difference.
The “Synthetic” Hedge: Using these engines to find a “Yes” on a prediction market and a “No” (or a different type of hedge) on a traditional sportsbook or financial exchange.
Scalping the Spread: Using real time comparison to “scalp” small price movements that happen on a fast exchange (like Solana based platforms) before they reflect on a slower one.

4 Arbitrage & Comparison Engines Tools for Prediction Markets

Eventarb

Indie Hacker

Type: Arbitrage & Comparison Engine (Arbitrage Calculator + Alerts)
Platform: Browser-based web tool
Primary Users: Prediction market arbitrageurs and traders seeking cross-platform pricing inefficiencies

What is Eventarb?

Eventarb is a cross-platform arbitrage calculation and alert tool that helps traders identify risk-free profit opportunities by comparing market odds for the same event across prediction markets such as Polymarket, Kalshi and even other venues like Robinhood. It focuses on detecting price disparities and quantifying potential spreads after fees.
Project type: Independent / Indie hacker type.
Targets: Pro traders & prosumers.
Monetization: Not clear yet.

Major and distinctive features:

Cross-Marketplace Discrepancy Calculator. Lets users input prices for the same event across multiple prediction markets and computes whether a risk-free arbitrage exists after accounting for fees, gas and other costs.
Arbitrage Alerts. Provides email-based alerts when new potential arbitrage opportunities arise, helping traders act quickly before markets converge.
Clear Breakdown of Math. Offers transparent calculations showing spreads, opportunity cost and potential returns for each arbitrage setup, which makes it educational as well as actionable.
Multi-Event & Multi-Venue Support. Capable of comparing binary and multi-outcome markets across different prediction venues such as Kalshi, Polymarket and non-traditional platforms (e.g., sports books added by users).
Delivery: Web app.

Arbitrage Scanner

Type: Arbitrage & Comparison Engine (Multi-Exchange Scanner with Alerts and API)
Platform: Browser-based service with optional Telegram and API integration
Primary Users: Pro traders & prosumers.
Monetization: Uses a subscription-based model with multiple plans (web, Telegram integration, advanced filters and API access).

What is ArbitrageScanner?

ArbitrageScanner.io is a crypto arbitrage scanning and analytics platform that identifies price differences (spreads) across dozens of exchanges and blockchains, providing traders with real-time alerts and detailed arbitrage opportunity feeds so they can act on inefficiencies.
Project type: The platform is built and marketed by ArbitrageScan Developers Ltd (a standalone project focused on arbitrage tools).
Targets: Pro traders and prosumers.

Major and distinctive features:

Multi-Exchange Arbitrage Scanning. Monitors price spreads across 40+ exchanges (CEX + DEX) and 20+ blockchains, alerting traders to where assets can be bought low and sold high on another venue.
Real-Time Alerts & Screener Tools. Includes spot, futures, funding-rate, and perpetual spread screens that update frequently so users can spot arbitrage windows, often notifying via web interface or Telegram.
APIs for Integration. Offers API access for developers who want to integrate arbitrage data into their own products, workflows or custom analytics dashboards.
Extended Analytics Modules. Beyond arbitrage scanning, the ecosystem also includes wallet analysis, sentiment tools, and cross-chain scanners, helping traders dig deeper into market behavior and potential signals.
Delivery: web application with optional Telegram alert integration and API access.

Polyscalping

Indie Hacker

Type: Arbitrage & Scalping Signal Engine
Platform: Web-based aggregator with alert support
Primary Users: Arbitrage hunters and scalping traders a.k.a pro traders and prosumers.

What is Polyscalping?

PolyScalping is a real-time arbitrage and scalping signal platform for Polymarket that scans all active markets to highlight pricing inefficiencies, tight spreads and potential profit opportunities so traders can act quickly when conditions align.
Project type: Independent / indie hacker tyope.
Targets: Pro traders and prosumers.
Monetization: Not clear yet.

Major and distinctive features:

Real-Time Market Scanner: Continuously scans Polymarket markets for arbitrage and scalping opportunities by monitoring metrics like volume, liquidity, and spread to surface markets that meet user defined criteria.
Custom Alerts & Notifications: Users can set price alerts and spread triggers so they receive instant signals (often via Telegram) when a profitable setup appears, helping them capitalize before the window closes.
ROI Calculator & Advanced Filters: Tools for estimating potential returns and filtering markets by volume, liquidity, and spread to prioritize opportunities that fit a trader’s risk/return profile.
Delivery: a web-based platform with optional alert integration (e.g., Telegram).

Matchr

Indie Hacker

Type: Arbitrage & Comparison Engine (Web Terminal with Cross-Market Scanner).
Platform: Web-based aggregator terminal.
Primary Users: Power users / pro traders.

What is Matchr?

Matchr is a cross-platform prediction market aggregator and execution assistant that lets users search, compare and track the same markets across multiple prediction exchanges (e.g., Polymarket, Kalshi) and spot price divergences and arbitrage opportunities.
Project type: Independent / Indie Hacker type.
Targets: Pro traders and prosumers.
Monetization: Not clear yet.

Major and distinctive features:

Cross-Market Search & Comparison. Matchr consolidates markets from different prediction platforms so users can compare odds, volumes and prices in real time from one interface.
Arbitrage Scanner (Beta). An experimental feature that uses intelligent matching to flag where two platforms (like Polymarket vs Kalshi) differ enough that a trader might profit by exploiting the gap;
Portfolio & Tracking Tools. Users can watch markets across venues from a single dashboard with price updates and potential divergence indicators.
Vaults Coming Soon. A future planned feature where users could deposit funds into managed vaults governed by smart contracts that execute strategies (including arbitrage or market-specific approaches) on their behalf.
Delivery: Matchr is delivered as a web-based platform.