Prediction Market Arbitrage: Live Cross-Platform Gap Finder

Buy both sides across Polymarket & Kalshi. Profit guaranteed.

Active Gaps

8.4 pts

Avg Gap

~$14.2K

Total Edge

Prediction market arbitrage is the practice of buying the same event on two platforms when their prices disagree, locking in a guaranteed profit regardless of the outcome. OddsShift scans 7,900+ markets across Polymarket and Kalshi in real time to find these cross-platform pricing gaps. When one platform prices an event at 62 cents and the other at 47 cents for the opposite outcome, the combined cost is less than $1 — creating a risk-free arbitrage opportunity. Last updated: April 2, 2026

Live Arbitrage Opportunities — Polymarket vs Kalshi Gaps cross-platform

Politics 2h ago · gap widening

Will Trump impose new tariffs by June 2026?

PM YES 72c

K YES 58c

14 pts gap +16.3% ROI

Details ›

World 5h ago · stable

Ukraine ceasefire agreement by May 2026?

PM YES 22c

K YES 35c

13 pts gap +14.9% ROI

Details ›

Finance 1h ago · gap narrowing

Fed rate cut before July 2026?

PM YES 41c

K YES 29c

12 pts gap +13.6% ROI

Details ›

Will Trump impose new tariffs by June 2026?

COST K YES 58c + PM NO 28c = 86c

PAYOUT One side always wins → $1.00

EDGE 14c profit · +16.3% ROI

Buy YES on Kalshi · 58c Buy NO on Polymarket · 28c

$2.1M volume · Closes Jun 30 · 98 days

Ukraine ceasefire agreement by May 2026?

COST PM YES 22c + K NO 65c = 87c

PAYOUT One side always wins → $1.00

EDGE 13c profit · +14.9% ROI

Buy YES on Polymarket · 22c Buy NO on Kalshi · 65c

$890K volume · Closes May 31 · 68 days

Fed rate cut before July 2026?

COST K YES 29c + PM NO 59c = 88c

PAYOUT One side always wins → $1.00

EDGE 12c profit · +13.6% ROI

Buy YES on Kalshi · 29c Buy NO on Polymarket · 59c

$3.4M volume · Closes Jul 15 · 113 days

Market

Correlated Market Inconsistencies logical arbitrage

When logically linked markets are priced inconsistently, it creates a mathematical impossibility. These mispricings are harder to spot but often more profitable than cross-platform gaps.

⚠ CONFLICT

Market A

Trump wins 2028 presidential election

60¢

Market B

Republican wins 2028 presidential election

48¢

Logic: If Trump wins (60%), a Republican must win (≥60%). But “Republican wins” is priced at only 48%. Mathematical impossibility.

Edge: Buy “Republican wins” YES at 48¢ — floor 60¢ = 12c edge +25% ROI

Trade Market A → Trade Market B →

⚠ CONFLICT

Market A

Fed cuts rates before July 2026

35¢

Market B

Fed cuts rates before October 2026

28¢

Logic: If “before July” (35%) implies “before October” must be ≥35%. But it’s priced at only 28%. The longer-dated market is underpriced.

Edge: Buy “before October” YES at 28¢ — floor 35¢ = 7c edge +25% ROI

Trade Market A → Trade Market B →

⚠ CONFLICT

Market A

Bitcoin above $100K by June 2026

63¢

Market B

Bitcoin above $80K by June 2026

58¢

Logic: If BTC > $100K (63%) then BTC > $80K must be ≥63%. But it’s priced at only 58%. The lower-threshold market is underpriced.

Edge: Buy “BTC > $80K” YES at 58¢ — floor 63¢ = 5c edge +8.6% ROI

Trade Market A → Trade Market B →

Arbitrage Profit Calculator estimate your edge

Platform A — YES price

Platform B — NO price

Est. total fees

Number of shares

Days to close

days

Combined cost per share:86¢

Gross profit per share:14¢

Fees per share:~2.6¢

Net profit per share:~11.4¢

Total profit (100 shares):~$11.40

ROI:~13.3%

APY (annualized):~53.9%

✅ Arbitrage opportunity — guaranteed profit of 14¢/share before fees

Actual results vary by platform fees, liquidity, and execution timing. View full OddsShift dashboard →

How Does Prediction Market Arbitrage Work? five steps

Find price disagreements

Look for the same event priced differently on Polymarket and Kalshi. If Polymarket prices “Will X happen?” at 72% and Kalshi prices it at 58%, there’s a 14-point gap.

OddsShift scans 7,900+ markets every 10 min

Calculate the combined cost

Buy YES on the cheaper platform and NO on the more expensive platform. Combined cost = YES price + (1 − NO price). If the combined cost is under $1.00, the difference is guaranteed profit.

Example: YES at 58¢ + NO at 28¢ = 86¢ → 14¢ profit

Account for platform fees

Both Polymarket and Kalshi charge fees that reduce your profit margin. Calculate net profit after fees on both platforms. Gaps under 3–4 points are typically not profitable after fees.

Polymarket: ~2% · Kalshi: varies by market

Execute both trades simultaneously

Speed matters — gaps can close quickly. Place both orders as close together as possible. Check liquidity on both sides before committing to ensure orders fill at expected prices.

High-liquidity gaps close in minutes · Low-liquidity: hours to days

Wait for market resolution

One of your positions wins and pays $1.00. The other pays $0. Your profit is $1.00 minus the combined cost minus fees. This profit is locked in regardless of the outcome.

Profit locked at entry · Outcome-independent

Is Polymarket Arbitrage Profitable in 2026? data-driven analysis

The Observer’s Analysis AI assessment

Cross-platform arbitrage between Polymarket and Kalshi is viable but requires discipline. Key findings from our continuous monitoring:

Profitable gaps (5+ points after fees) appear 15–25 times per week across 7,900+ markets
Average gap duration is 18 hours for liquid markets, up to 3 days for niche events
Kalshi tends to lag Polymarket on breaking news — gaps often appear first on PM then K follows
Logical arbitrage (correlated market mispricings) offers higher returns but requires deeper analysis
Primary risk: execution speed — by the time you trade both sides, the gap may narrow

Our AI Observer uses gap data to inform its own real-money trades. See our verified trading performance on the main dashboard.

Frequently Asked Questions about prediction market arbitrage

How does prediction market arbitrage work?

Prediction market arbitrage exploits price differences when platforms like Polymarket and Kalshi disagree on the same event. For example, if Polymarket prices an event at 72% and Kalshi prices it at 58%, you can buy YES on one and NO on the other for a combined cost under $1.00, guaranteeing profit regardless of the outcome.

Is Polymarket arbitrage profitable?

Cross-platform arbitrage between Polymarket and Kalshi can be profitable when price gaps are large enough to cover fees on both platforms. Cross-platform scanners like OddsShift track 7,900+ markets to surface the largest gaps. Gaps of 5+ points are relatively common, though actual returns depend on fees, timing, and liquidity.

What tools can I use for prediction market arbitrage?

OddsShift is a cross-platform prediction market scanner that shows real-time price gaps between Polymarket and Kalshi across 7,900+ markets. Other tools include ArbBets for automated arbitrage alerts and OddPool for odds comparison across platforms.

What are the risks of cross-platform prediction market arbitrage?

Key risks include: timing risk (prices change before you execute both sides), resolution risk (platforms may resolve the same event differently), liquidity risk (insufficient volume to fill orders), and platform risk (withdrawal delays or restrictions). Fee differences between Polymarket and Kalshi can also eat into margins on small gaps.

How fast do prediction market arbitrage gaps close?

Arbitrage gaps between Polymarket and Kalshi typically close within minutes to hours for high-liquidity markets. For less liquid markets, gaps of 5–15 points can persist for days. OddsShift tracks gap persistence and analyzes which platform’s price tends to converge to the final outcome.

Platform Comparison

Full platform comparison — live odds, fees, and volume across 7,900+ markets

Compare Platforms →

Accuracy Tracker

Platform accuracy track record — resolution data by category

See Accuracy →

Getting Started

New to prediction markets? Step-by-step guide for Polymarket & Kalshi

Start Here →

OddsShift pays for itself on trade #2

Subscribe — $29/month