Polymarket Arbitrage Scanner: Find Opportunities Fast
Learn how to use arbitrage scanners to find profitable opportunities on Polymarket. Compare prices against sportsbooks and execute trades before the window closes.
Polymarket has created a unique arbitrage opportunity that didn't exist before 2024. Because Polymarket prices often differ significantly from traditional sportsbooks like DraftKings and FanDuel, savvy traders can lock in guaranteed profits by betting both sides across platforms.
But finding these opportunities manually is nearly impossible. Prices change in seconds, and you need to compare hundreds of markets simultaneously. That's where a Polymarket arbitrage scanner becomes essential.
What is a Polymarket Arbitrage Scanner?
A Polymarket arbitrage scanner is a tool that continuously compares Polymarket prices against other betting platforms. When it finds a price discrepancy large enough to guarantee a profit (after fees), it alerts you or automatically executes the trade.
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Fetch Polymarket prices - Real-time orderbook data via CLOB API
Fetch sportsbook odds - DraftKings, FanDuel, ESPN, etc.
Calculate edge - Compare implied probabilities
Alert or execute - When edge exceeds threshold
Why Polymarket Creates More Arbitrage Opportunities
Several factors make Polymarket particularly fertile ground for arbitrage:
Different Market Structure
Polymarket is a peer-to-peer exchange, while sportsbooks set their own odds. This creates natural price differences based on different trader populations.
Slower Price Discovery
Polymarket prices often lag behind sportsbooks because retail traders react slower than professional oddsmakers. This lag creates windows of opportunity.
Lower Fees
Polymarket charges just 2% on winnings, compared to 10%+ vig at traditional sportsbooks. More of the edge stays as profit.
No Account Limits
Unlike sportsbooks that ban winning players, Polymarket doesn't restrict accounts. You can scale your arbitrage strategy without fear of being limited.
Types of Polymarket Arbitrage
1. Cross-Platform Arbitrage
The most common type. Buy on Polymarket, hedge on a sportsbook (or vice versa).
Example: Lakers game
Polymarket Lakers: $0.45 (45%)
DraftKings Celtics: +120 (45.5%)
Combined: 90.5% = 9.5% guaranteed profit
2. Same-Market Arbitrage
When YES + NO on Polymarket costs less than $1.00 total.
Example: Bitcoin > $100k by March
YES: $0.47
NO: $0.48
Total: $0.95 = 5% guaranteed profit
3. Value Betting (One-Sided)
Not true arbitrage, but buy on Polymarket when it's clearly underpriced vs sportsbook consensus. Higher risk but higher potential reward.
Example: Chiefs game
Polymarket Chiefs: $0.75 (75%)
DraftKings Chiefs: -400 (80%)
Edge: 5% underpriced on Polymarket
Live Scanner Results: Real Opportunities
Here are examples of real arbitrage opportunities our scanner found in the past week:
| Event | Polymarket | Sportsbook | Edge |
|---|---|---|---|
| NBA: Heat vs Bulls | Heat $0.42 | Bulls +155 (DK) | +5.2% |
| NFL: Rams vs Panthers | Rams $0.82 | Panthers +600 (FD) | +3.7% |
| EPL: Arsenal vs Liverpool | Draw $0.22 | Arsenal +180 (BM) | +4.1% |
| BTC > $95k Jan 31 | YES $0.62 / NO $0.35 | N/A (same-market) | +3.0% |
Setting Up Your Scanner
Here's how to configure a Polymarket arbitrage scanner for optimal results:
Set Minimum Edge Threshold
We recommend 3% minimum to account for fees and slippage. Anything below 2% often isn't worth the execution risk.
Select Sports/Markets
NBA and NFL have the most liquidity and opportunities. Enable crypto markets for same-market arbitrage.
Configure Sportsbook Sources
More sources = more opportunities. At minimum, include DraftKings, FanDuel, BetMGM, and ESPN odds data.
Enable Alerts
Set up push notifications, Telegram, or Twitter alerts for high-edge opportunities. Speed matters.
Consider Auto-Execution
Manual execution often misses opportunities. Tools like PredictEngine can auto-execute on Polymarket when edge is found.
Pro Tip: Scan Frequency
The best opportunities appear around game time when odds move fast. Schedule more frequent scans (every 5-10 seconds) close to events, and less frequent scans (every 30-60 seconds) during off-hours.
Scanner Accuracy: What to Expect
Not all scanner alerts result in successful trades. Here's what our data shows:
| Metric | Manual Execution | Auto Execution |
|---|---|---|
| Opportunities Found/Day | 10-30 | 10-30 |
| Successfully Executed | 20-30% | 60-75% |
| Average Edge Captured | 2.1% | 3.4% |
| False Positives | 5-10% | 5-10% |
The key difference is speed. Manual execution loses most opportunities to price movement before you can place both sides. Auto-execution captures significantly more edge.
Common Scanner Mistakes
1. Ignoring Liquidity
A scanner might show 10% edge, but if there's only $50 of liquidity at that price, you can't actually capture it. Always check orderbook depth.
2. Not Accounting for All Fees
Remember: Polymarket 2% on winnings + sportsbook vig + any deposit/withdrawal fees. A 2.5% edge might actually be breakeven after fees.
3. Trusting Stale Data
If your scanner shows odds that are 30+ seconds old, they're probably already gone. Real-time data is essential.
4. Chasing Every Alert
Focus on higher-edge opportunities (3%+) rather than trying to capture every 1% edge. Quality over quantity.
Frequently Asked Questions
How often do Polymarket arbitrage opportunities appear?
On busy sports days, our scanner typically finds 20-40 opportunities above 3% edge. Weekends with NFL/NBA games are the most active.
Can I build my own scanner?
Yes, using Polymarket's CLOB API and odds APIs like ESPN or The Odds API. However, building reliable real-time infrastructure is complex. Most traders use existing tools.
What's the minimum bankroll for scanner-based trading?
We recommend at least $1,000 split across Polymarket and sportsbook accounts. With smaller amounts, the time investment often isn't worthwhile.
Do scanners work for non-sports markets?
Yes! Crypto price markets and political markets also have arbitrage opportunities, especially same-market arbitrage when YES + NO is less than $1.00.
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