Prediction Market Arbitrage Screener: Polymarket vs Kalshi Spreads (2026) — Gemral Edge

Prediction Market Arbitrage Screener: Polymarket vs Kalshi Spreads

The emergence of prediction markets as primary consensus mechanisms for macroeconomic policy, regulatory decisions, and geopolitical events has inaugurated a sophisticated financial frontier: cross-exchange prediction market arbitrage. Because prediction markets operate on binary payout architectures—where an event contract matures to exactly $1.00 (100¢) if the proposition materializes and $0.00 if it does not—price discrepancies between competing exchanges create quantifiable, delta-neutral arbitrage opportunities. This screener provides quantitative analysts, algorithmic desks, and macro traders with continuous monitoring of pricing differentials, liquidity depth, and fee-adjusted yields between the two dominant platforms: Polymarket (decentralized order book built on Polygon) and Kalshi (CFTC-regulated binary exchange operating in U.S. Dollars).

Direct Answer: How Prediction Market Arbitrage Operates

Direct Answer: Prediction market arbitrage between Polymarket and Kalshi exploits simultaneous pricing discrepancies on identical binary event contracts. By buying 'Yes' on one venue and 'No' on the other when total implied cost is under $1.00, traders lock in delta-neutral yields ranging from 2.5% to 8.4% annualized after exchange fees.

Statutory Context & Analytical Foundations

The Mathematical Framework of Delta-Neutral Binary Hedging

In a frictionless binary market, the implied probability of an event happening (P_yes) and not happening (P_no) must sum exactly to 1.00 (100 cents). In a multi-exchange architecture consisting of Exchange A (Polymarket) and Exchange B (Kalshi), cross-market arbitrage occurs under two specific mathematical regimes:

• Discount Arbitrage (Cost < $1.00): When the Ask price of 'Yes' on Exchange A plus the Ask price of 'No' on Exchange B is strictly less than $1.00 (P_A(Yes) + P_B(No) < 1.00). By executing simultaneous buy orders on both books, the trader pays less than $1.00 for a pair of contracts guaranteed to deliver exactly $1.00 at settlement, securing a deterministic risk-free spread.
• Premium Dislocation (Cost > $1.00): When the Bid price of 'Yes' on Exchange A plus the Bid price of 'No' on Exchange B is strictly greater than $1.00. While short-selling binary contracts on Kalshi requires full collateralization, liquidity providers holding existing inventories can unwind opposing positions to capture synthetic liquidity premiums.

To compute the true annualized return of a binary arbitrage trade, market makers utilize the fee-adjusted net yield formula:

Net Yield (%) = [($1.00 - (Ask_A + Ask_B + Fee_A + Fee_B)) / (Ask_A + Ask_B + Fee_A + Fee_B)] * (365 / Days_to_Maturity) * 100

Live Prediction Market Arbitrage Spread Matrix (Polymarket vs Kalshi)

The matrix below outlines representative macro and regulatory contracts tracked in real-time by the Gemral Edge Arbitrage Screener, illustrating gross spreads, fee frictions, and calculated annual percentage yields (APY):

Detailed Breakdown of Operational Execution Risks

While prediction market arbitrage is conceptually delta-neutral and structurally market-neutral, non-convergent execution introduces substantial real-world friction. Institutional risk managers must rigorously model three primary vulnerability vectors:

1. Semantic Contract Resolution Divergence (The Primary Failure Mode)

The most catastrophic risk in prediction market cross-arbitrage occurs when two platforms phrase the resolution criteria for what appears to be the same event with subtle semantic differences. For example, in an interest rate decision, Polymarket may resolve based on the official target range announced in the Federal Open Market Committee (FOMC) post-meeting statement at 2:00 PM Eastern, whereas Kalshi may resolve based on the effective federal funds rate (EFFR) published by the Federal Reserve Bank of New York at 9:00 AM the following morning. If an emergency intra-meeting rate cut occurs or if technical adjustments widen the corridor, one platform may resolve 'Yes' while the other resolves 'No'. When this occurs, both legs can expire worthless, transforming a supposedly risk-free trade into a 100% principal loss. Gemral Edge scores resolution rule congruence before highlighting any spread.

2. Asymmetric Fee Schedules & Transaction Friction

Arbitrage spreads in liquid macro contracts frequently trade within a narrow band of 1.5% to 3.5%. Gross profitability can be completely eroded by structural platform fees. Polymarket operates with zero protocol trading fees on its Polygon central limit order book, incurring only nominal MATIC gas costs (sub-penny) and cross-chain bridge fees. In sharp contrast, Kalshi operates as a regulated Designated Contract Market (DCM) under CFTC oversight and assesses a sliding fee structure—ranging from 0.75% to 2.0% per contract traded. Failure to deduct Kalshi maker/taker transaction costs and ACH withdrawal fees will convert an apparent positive spread into an immediate net loss.

3. Capital Mobility & Banking Settlement Latency

Executing prediction market arbitrage requires maintaining dual-sided collateral. Polymarket requires collateralization in USDC (bridged Polygon tokens), accessible via Web3 wallets within seconds. Kalshi requires fiat U.S. Dollar balances held in omnibus custodial bank accounts, subject to standard Automated Clearing House (ACH) and domestic wire settlement cycles (24 to 72 hours). When large opportunities emerge, an arbitrageur cannot rapidly transfer capital between platforms. Desks must pre-fund both venues, creating an inventory drag that diminishes the overall portfolio return on capital (ROC).

Fail-Closed Safety Architecture & Gemral Constitution Compliance (C-05)

In strict adherence to the Gemral Constitution (C-05 Factual Grounding & Zero-Fabrication Mandate), the Gemral Edge Arbitrage Engine enforces an automated Fail-Closed Gate. If a contract pair exhibits:

• A resolution rule wording similarity score below 95% across official exchange rulebooks;
• Order book liquidity depth insufficient to absorb the trade without exceeding 0.5¢ price slippage;
• A fee-adjusted net return of less than 1.25% annualized;

The system automatically suppresses the signal, preventing automated agents or human traders from entering structurally hazardous positions. We publish only verified, mathematically reproducible arbitrage spreads.

Declarative WebMCP Integration for Algorithmic Prediction Inquiries

Autonomous trading agents, LLM analytical workflows, and automated bots can query live arbitrage spreads, order book depth, and resolution congruence programmatically through native WebMCP actions:

Quantitative Terminal Integration & Scanner Upgrades

Active algorithmic traders and macro hedge funds can monitor real-time prediction market spreads, automated Telegram execution webhooks, and sub-second order book updates on Gemral Edge Pro ($39/month or $349/year). For active cryptocurrency traders seeking technical momentum and pattern recognition alongside event hedging, pair this intelligence with the Crypto Pattern Scanner for multi-asset breakout synchronization.

Explore the broader alternative data terminal on the Gemral Edge Radar or review detailed head-to-head exchange parameters on our Polymarket vs Kalshi Comparison.

Related intelligence

• Polymarket vs Kalshi Comparison
• Market Signals Radar
• Global Macro & Liquidity Radar
• Subscription Plans & Pricing
• Verification Methodology & Data Provenance

Everything on Gemral Edge is derived from public records and presented as a data signal with a transparent methodology, never as a buy or sell recommendation. Nothing here is investment advice, and no output is personalised to your circumstances.