Polymarket vs. Kalshi vs. DraftKings Predictions: Every Prediction Market Compared

Three platforms, three philosophies. Polymarket is the crypto-native liquidity leader. Kalshi is the CFTC-regulated pioneer. DraftKings Predictions is the mass-market disruptor. Together they define prediction market trading in 2026.

Prediction markets are no longer a niche. By early 2026, three platforms dominate the landscape — each with a fundamentally different approach to the same core product: binary event contracts that let you trade on real-world outcomes. Polymarket built the largest prediction market in history using blockchain infrastructure and a global user base. Kalshi created the US regulatory playbook as the first CFTC-designated contract market for event contracts. DraftKings Predictions brought event contracts to the masses through the most recognizable brand in American sports betting.

This comparison covers every dimension that matters: regulation, market coverage, API access, fees, liquidity, user experience, and — most critically for the AgentBets audience — AI agent compatibility. Whether you are a retail trader choosing a platform, a developer building an automated system, or an institution evaluating the space, this is the definitive reference.

For the head-to-head between the two regulated platforms specifically, see our Kalshi vs. DraftKings Predictions comparison. For the broader context of how sportsbooks and prediction markets are converging, see our convergence guide.

Quick Verdict

Polymarket — Best for liquidity, global access, developer API, and the widest market selection. The go-to for serious traders and AI agent developers who can tolerate regulatory ambiguity.

Kalshi — Best for US regulatory clarity, institutional-grade trading, and the most mature API among regulated platforms. The choice for anyone who needs a CFTC-regulated counterparty.

DraftKings Predictions — Best for consumer experience, sportsbook integration, and long-term retail liquidity potential. The choice for casual traders and anyone already in the DraftKings ecosystem.

Three Platforms, Three Philosophies

Polymarket

Polymarket operates on the Polygon blockchain, using USDC (a US dollar stablecoin) as its base currency. Contracts are tokenized and traded through a Central Limit Order Book (CLOB) with settlement on-chain. The platform was founded in 2020 by Shayne Coplan and gained mainstream attention during the 2024 US presidential election, when its markets became the most-cited prediction source in media coverage worldwide.

Polymarket does not hold a CFTC license and is not available to US residents through its main interface (though enforcement of geographic restrictions on blockchain platforms is imperfect). The platform serves a global audience and has attracted the deepest liquidity in the prediction market space, driven by crypto-native traders, institutional desks, and a growing ecosystem of automated bots.

For a deep dive into Polymarket’s API, see our Polymarket API guide.

Kalshi

Kalshi is a CFTC-regulated Designated Contract Market (DCM) — the same regulatory designation held by the CME Group and ICE. Founded in 2018 by Tarek Mansour and Luana Lopes Lara, Kalshi launched in 2021 and has methodically expanded its market coverage across politics, economics, weather, science, and sports. The platform operates as a traditional financial exchange with order books, limit orders, and institutional connectivity through the FIX protocol.

Kalshi’s regulatory clarity is its defining advantage: US traders can use the platform with full legal certainty, deposits are held in regulated accounts, and contract settlement is governed by CFTC rules. The trade-off is geographic limitation (US only) and market approval constraints (each new category requires CFTC review).

For integration guidance, see our Kalshi API guide.

DraftKings Predictions

DraftKings Predictions entered the event contract space through the acquisition of Railbird, which held its own CFTC DCM designation. The product is integrated into the DraftKings ecosystem alongside DraftKings Sportsbook, DraftKings Casino, and DraftKings Daily Fantasy. This integration means event contracts are presented to a user base that already numbers over 20 million accounts.

DraftKings Predictions benefits from brand recognition, a polished mobile experience, shared wallet infrastructure, and cross-product promotional capabilities. The strategic vision is straightforward: if you bet on sports with DraftKings, event contracts are a natural extension of what you already do.

For a detailed platform analysis, see our DraftKings Predictions review.

Master Comparison Table

Regulation Deep Dive

Regulation is the single most important differentiator across these three platforms, and it determines who can use each one, what protections exist, and how markets are approved.

Polymarket: Blockchain-Native, Regulatory Gray Area

Polymarket operates without a specific financial services license. It is built on blockchain infrastructure and uses cryptocurrency for settlement. The platform reached a settlement with the CFTC in 2022 and officially geo-blocks US IP addresses, but because it is a decentralized protocol, enforcement of geographic restrictions is inherently limited.

For traders, this means:

• No CFTC protections. Funds are not held in regulated accounts. In the event of a platform failure or dispute, there is no US regulatory body to appeal to.
• No KYC requirement for basic trading (though large withdrawals may trigger compliance reviews).
• Broader market coverage. Without needing CFTC approval for each contract, Polymarket can launch markets on any event rapidly.
• Global access. Anyone with a crypto wallet and USDC can trade.

Kalshi: Full CFTC Regulation

Kalshi’s DCM designation means:

• Segregated customer funds. Deposits are held in accounts separate from Kalshi’s operating funds, protected by CFTC rules.
• Market integrity oversight. The CFTC reviews and approves contract specifications. Manipulation is a federal offense.
• Full KYC/AML compliance. Every user must verify identity with SSN and government ID.
• Market approval process. New event categories require CFTC review, which can be slow but ensures legal clarity.

DraftKings Predictions: CFTC Regulation with State Licensing

DraftKings Predictions inherits its DCM status from the Railbird acquisition and also benefits from DraftKings’ extensive state-by-state licensing infrastructure. This dual regulatory framework means:

• Same CFTC protections as Kalshi. Segregated funds, market integrity oversight, federal regulatory backing.
• State-level compliance. DraftKings already maintains licenses in most US states, simplifying the rollout of event contracts.
• Shared compliance infrastructure. KYC/AML processes are already in place for the broader DraftKings platform.

What This Means for Traders

If regulatory protection is your top priority, Kalshi and DraftKings Predictions are your options. If you are comfortable with blockchain-native platforms and want the deepest liquidity and widest market selection, Polymarket is the leader. For a broader discussion of the sports betting regulatory landscape and how prediction markets fit in, see our guide to sports betting vs. prediction markets.

Market Coverage: Who Covers What

Political Markets

All three platforms cover major political events, but depth varies:

• Polymarket dominates political market liquidity. Presidential election markets have seen individual event volumes exceeding $1 billion. Coverage extends to congressional races, state elections, international politics, and policy-specific questions.
• Kalshi has deep political coverage following its federal court victory allowing election contracts. Congressional, gubernatorial, and policy markets are well-covered with institutional liquidity.
• DraftKings Predictions covers high-profile political events (presidential, major Senate races) but lacks the depth on niche political markets that Polymarket and Kalshi offer.

Economic Markets

• Kalshi leads decisively. Markets on Fed rate decisions, CPI, GDP, employment data, and other economic indicators are a core strength, with institutional market makers providing tight spreads.
• Polymarket has growing economic coverage, particularly around Fed decisions and inflation.
• DraftKings Predictions covers major economic events but without the depth that institutional traders require.

Sports and Entertainment

• DraftKings Predictions has a structural advantage here, leveraging the DraftKings brand and sportsbook cross-selling. Sports milestone contracts, award predictions, and entertainment events are natural fits.
• Polymarket offers sports and entertainment markets, though with less focus than political and crypto categories.
• Kalshi has expanded into sports and entertainment, particularly after securing the right to list sports-related event contracts.

Crypto and Technology

• Polymarket dominates. Markets on Bitcoin price milestones, Ethereum upgrades, DeFi protocol events, and technology launches attract the crypto-native user base.
• Kalshi offers some technology markets (AI milestones, product launches) but does not cover crypto price events.
• DraftKings Predictions has minimal presence in crypto or technology markets.

Weather and Science

• Kalshi pioneered weather derivatives for retail traders — temperature records, hurricane landfall, snowfall totals.
• Polymarket has some weather markets, primarily around record-breaking events.
• DraftKings Predictions covers major weather events but without the depth of Kalshi’s systematic weather contracts.

API and Developer Comparison

This is the most important section for anyone building automated trading systems, AI agents, or data pipelines. The API gap between platforms is the single largest differentiator for the AgentBets audience.

Polymarket API

Polymarket’s CLOB API is the most developer-accessible prediction market API available:

• py-clob-client. Official Python SDK maintained by Polymarket. Full support for order placement, cancellation, market data retrieval, and portfolio management. This is the foundational tool for the majority of Polymarket bots. See our py-clob-client reference guide for details.
• REST endpoints. Market discovery, price data, order book snapshots, trade history.
• WebSocket feeds. Real-time streaming for order book updates and trade notifications.
• On-chain data. Because Polymarket operates on Polygon, all settlement data is on-chain and queryable through standard blockchain APIs (Etherscan, The Graph, custom RPC nodes).
• No rate limit throttling for reasonable usage. Polymarket’s API is designed for bot traffic and handles high-frequency queries gracefully.
• Gamma API. A separate API for market metadata, resolution information, and historical data.

Agent compatibility: Excellent. The vast majority of prediction market agents in production today use Polymarket as their primary or sole platform. The combination of py-clob-client, on-chain transparency, and bot-friendly policies makes it the default choice for developers.

Kalshi API

Kalshi’s API is the most sophisticated among regulated platforms:

• REST API. Comprehensive endpoints for market data, order management, position tracking, and account operations. Well-documented with code examples and error handling guidance.
• FIX protocol. Industry-standard Financial Information eXchange protocol for institutional-grade connectivity. Ultra-low latency, streaming market data, drop-copy execution reports.
• WebSocket feeds. Real-time order book and trade data streaming.
• Official Python SDK. Maintained by Kalshi, wrapping the REST API for common operations.
• Sandbox environment. A paper-trading environment for testing API integrations without risking real capital.
• Published rate limits. Clear documentation of request limits and throttling behavior.

Agent compatibility: Strong. Kalshi is the best option for agents that require US regulatory compliance. The REST API handles most use cases; FIX protocol serves institutional agents needing maximum performance. Our Kalshi API guide covers the full integration process.

DraftKings Predictions API

DraftKings Predictions is the least mature on the API front:

• Limited public API. Market data endpoints exist but a fully documented trading API is not yet generally available.
• No FIX protocol. Institutional-grade connectivity is not a current offering.
• No official SDK. Developers must build their own integrations from available endpoints.
• No sandbox environment for testing.
• API documentation is minimal compared to Polymarket and Kalshi.

Agent compatibility: Limited. As of early 2026, building a fully automated trading agent on DraftKings Predictions requires significant reverse-engineering effort. This will improve as DraftKings invests in developer tooling, but it is not production-ready today.

API Comparison Table

For a comprehensive technical comparison of all prediction market APIs, see our unified API comparison guide.

Fees and Cost Analysis

Fee structures vary significantly and impact strategy profitability, especially for high-frequency or arbitrage agents.

Polymarket Fees

• Maker fees: 0% — placing limit orders that add liquidity is free.
• Taker fees: Approximately 2% on orders that remove liquidity from the book.
• Gas fees: Minimal on Polygon (fractions of a cent per transaction), though bridging USDC to Polygon from Ethereum mainnet costs more.
• No deposit or withdrawal fees beyond blockchain gas costs.
• No settlement fees.

The 0% maker fee makes Polymarket extremely attractive for market-making agents and strategies that primarily use limit orders. Taker fees are competitive with other financial exchanges.

Kalshi Fees

• Exchange fee: $0.01 per contract per side (entry and exit/settlement).
• No deposit or withdrawal fees for standard ACH.
• No inactivity fees.
• Wire transfer fees for expedited withdrawals.

Kalshi’s fee structure is simple and predictable. The fixed per-contract fee favors larger trades on contracts priced near the extremes ($0.90+), where the fee is a smaller percentage of notional value.

DraftKings Predictions Fees

• No explicit per-contract fee.
• Spread-based pricing — the platform’s take rate is built into the bid-ask spread.
• DraftKings wallet transactions follow standard DraftKings banking terms.
• Promotional credits may offset effective costs for some users.

Fee Impact Analysis for a $1,000 Monthly Trading Volume

For limit-order strategies (market making, patient entry), Polymarket is cheapest. For all order types with a focus on cost predictability, Kalshi offers the lowest and most transparent fees. DraftKings Predictions costs are harder to forecast but may be offset by promotional value.

Liquidity Analysis

Liquidity determines how large a position you can take without moving the market, and how quickly you can exit.

Polymarket: Liquidity Leader

Polymarket has the deepest prediction market liquidity in the world. Key factors:

• Global user base spanning crypto-native traders, institutional desks, and automated bots.
• Market-making incentives through 0% maker fees attract professional liquidity providers.
• Volume concentration on high-profile events creates deep order books — presidential election markets have seen individual-event volume exceeding $1 billion.
• Active bot ecosystem provides continuous liquidity even on quieter markets.
• 24/7 trading with no market hours restrictions.

Liquidity is highly uneven across markets. Political and crypto events have deep books; niche topics may have minimal liquidity.

Kalshi: Institutional Liquidity

Kalshi’s liquidity profile differs:

• Professional market makers connected via FIX protocol provide continuous two-sided quotes on popular markets.
• Institutional flow from trading firms and hedge funds adds depth to economic and political markets.
• Growing retail base contributes increasing organic flow.
• Event-driven spikes around elections and economic releases create temporary deep liquidity.

Kalshi’s liquidity is concentrated in economic indicators and high-profile political events. The FIX protocol infrastructure attracts the type of market makers who provide meaningful depth.

DraftKings Predictions: Potential vs. Current

DraftKings Predictions has the most untapped liquidity potential:

• 20+ million existing accounts represent a vast pool of potential traders.
• Cross-product discovery drives organic conversion from sportsbook to event contracts.
• Brand trust lowers the barrier for first-time prediction market participation.
• Marketing resources can drive awareness campaigns that smaller platforms cannot match.

Current liquidity is thinner than both competitors, which is expected for a platform that launched recently. The trajectory depends on conversion rates — how many DraftKings users actually engage with event contracts.

Liquidity by Category

Cross-Platform Arbitrage Strategy

The existence of three major platforms with different user bases, fee structures, and settlement mechanics creates persistent cross-platform arbitrage opportunities. This is one of the most compelling use cases for AI agents in prediction markets.

Why Arb Exists Across These Platforms

Price discrepancies arise because:

1. Different user bases. Polymarket’s crypto-native traders price events differently than Kalshi’s institutional participants or DraftKings’ retail sports bettors.
2. Different information flows. Crypto-native users may react faster to crypto-related news; sportsbook users may have better intuition on sports-adjacent events.
3. Different fee structures. A contract trading at $0.55 on a 0%-fee platform has a different effective cost than the same contract at $0.55 on a 2%-fee platform, which means equilibrium prices differ.
4. Settlement currency differences. USDC on Polymarket vs. USD on Kalshi and DraftKings introduces currency risk and conversion friction that prevents instant arbitrage closure.
5. Regulatory restrictions. US traders cannot easily access Polymarket, which segments the user pools and maintains price gaps that would otherwise be arbitraged away.

Three-Platform Arb Architecture

An AI agent designed for cross-platform arbitrage across all three platforms needs:

1. Multi-platform data ingestion. Real-time price monitoring on Polymarket (via CLOB API), Kalshi (via REST/WebSocket), and DraftKings Predictions (via available endpoints).
2. Contract matching engine. An automated system that identifies equivalent contracts across platforms, accounting for differences in contract wording, resolution criteria, and expiration dates.
3. Fee-adjusted pricing model. The agent must calculate the effective price on each platform after accounting for fees, ensuring the arb is profitable net of all costs.
4. Execution layer. Order placement on each platform through its respective API — py-clob-client for Polymarket, Kalshi SDK for Kalshi, and whatever DraftKings endpoint is available.
5. Currency management. Maintaining USDC balances for Polymarket and USD balances for Kalshi/DraftKings, with a strategy for rebalancing between the two.
6. Risk management. Position limits, exposure monitoring, and circuit breakers to prevent the agent from accumulating excessive one-sided risk.

Practical Arb Example

Fed rate decision contract — will the Fed cut rates at the June 2026 meeting?

Arb opportunity: Buy YES on Polymarket at $0.58 + Buy NO on Kalshi at $0.38 = $0.96 total cost for a guaranteed $1.00 payout. Gross profit: $0.04 per paired contract. After Polymarket taker fee (~$0.012) and Kalshi exchange fee ($0.02): net profit approximately $0.008 per pair, or 0.8% risk-free return.

Small per-contract, but at scale with automated execution, these opportunities compound. For a complete guide to building cross-platform arb systems, see our cross-platform arbitrage strategy guide.

Agent Architecture for Multi-Platform Trading

For developers building AI agents that operate across all three platforms, here is the recommended architecture:

Unified Abstraction Layer

Build a platform-agnostic interface that normalizes:

• Market representation. A common data model for events, contracts, and prices regardless of source platform.
• Order interface. A unified order object that the agent works with, translated to platform-specific API calls by adapter modules.
• Portfolio tracking. Consolidated position and P&L tracking across all three platforms.
• Risk management. Cross-platform exposure monitoring and position limits.

Platform Adapters

Each platform requires its own adapter module:

Polymarket adapter:

• Uses py-clob-client for order execution
• WebSocket for real-time price data
• Polygon RPC for on-chain settlement verification
• USDC balance management

Kalshi adapter:

• Uses Kalshi Python SDK for REST API operations
• WebSocket for streaming market data
• FIX protocol adapter for institutional-grade execution (optional)
• USD balance management

DraftKings adapter:

• Custom HTTP client for available API endpoints
• Web scraping fallback for data not available via API (with rate limiting)
• USD balance management through DraftKings wallet

Intelligence Layer

The agent’s decision-making logic sits above the platform adapters and works with the unified data model:

• Signal generation. Combine data from all three platforms (price, volume, order book depth) with external data sources (news, polling, economic indicators).
• Opportunity identification. Cross-platform price comparison for arb; single-platform analysis for directional trades.
• Execution routing. Route orders to the platform offering the best combination of price, liquidity, and fee efficiency.
• Performance attribution. Track which platform and strategy combinations generate the most alpha.

Browse our agent marketplace for pre-built tools and frameworks that support multi-platform architectures.

Decision Framework: Which Platform for Which User

Solo Retail Trader (US-Based)

Start with Kalshi. Full regulatory protection, straightforward onboarding, and a platform designed for individual traders. Add DraftKings Predictions if you already use DraftKings for sports betting.

Solo Retail Trader (International)

Start with Polymarket. Global access, deepest liquidity, lowest fees for limit orders, and no geographic restrictions. The only realistic option for non-US retail traders.

AI Agent Developer (Beginner)

Start with Polymarket. The py-clob-client SDK has the most community support, the most tutorials, and the most open-source examples. Getting a basic bot running on Polymarket is faster than any other platform.

AI Agent Developer (Production)

Use both Polymarket and Kalshi. Polymarket for maximum liquidity and market breadth. Kalshi for regulated market access and institutional-grade execution. Monitor DraftKings Predictions for when its API matures.

Institutional Trader / Fund

Use all three. Polymarket for liquidity, Kalshi for regulation and FIX protocol, DraftKings Predictions for retail flow access. The cross-platform arbitrage opportunities alone justify maintaining accounts on all platforms.

Sportsbook Cross-Over Trader

Start with DraftKings Predictions. The ability to compare event contract prices with sportsbook odds within a single platform creates unique analytical advantages. Add Kalshi for markets DraftKings does not cover.

Arbitrage Specialist

You need all three. The more platforms you monitor, the more arb opportunities you find. The largest and most persistent arbs exist between platforms with different user bases — which means Polymarket-to-Kalshi and Polymarket-to-DraftKings arbs are typically larger than Kalshi-to-DraftKings arbs. See our cross-platform arbitrage guide for implementation details.

The Convergence Thesis

These three platforms represent three points on a spectrum that is slowly converging. Polymarket is moving toward more structured compliance. Kalshi is expanding market coverage and accessibility. DraftKings is bridging the gap between sports betting and prediction markets.

The convergence of sportsbooks and prediction markets — a trend we cover in depth in our convergence guide — means these categories will increasingly overlap. Sports bettors are discovering event contracts. Prediction market traders are exploring sportsbook odds. AI agents are arbitraging across all of them.

The winner of this three-way competition may not be a single platform. The prediction market opportunity is large enough — and the user base differences are structural enough — that all three platforms can thrive by serving different segments. For AI agent developers, the optimal strategy is not picking a winner; it is building systems that operate across all three platforms and capture the value that exists at the intersection.

Frequently Asked Questions

What is the best prediction market platform in 2026?

It depends on your priorities. Polymarket leads in liquidity, market variety, and developer API access but operates in a regulatory gray area for US users. Kalshi is the best for US users who want regulatory clarity and institutional-grade API access. DraftKings Predictions combines event contracts with sportsbook access for the most versatile betting and prediction experience. For AI agent developers, Polymarket and Kalshi tie for best API access; DraftKings is catching up.

Can AI agents trade on all three platforms?

Polymarket offers the most accessible API for automated trading through its full CLOB client and Python SDK (py-clob-client). Kalshi provides a REST API, FIX protocol, and WebSocket feeds with comprehensive documentation. DraftKings Predictions API is still developing, making fully automated trading more difficult. All three platforms can be monitored by agents for cross-platform arbitrage opportunities, even if execution is only automated on Polymarket and Kalshi.

Which prediction market has the most liquidity?

Polymarket dominates overall liquidity, especially on political and crypto markets, with total volume exceeding $1 billion on major events. Kalshi has the deepest regulated-market liquidity, particularly on economic indicators and high-profile political events. DraftKings Predictions is newest but has the largest potential retail user base given DraftKings’ 20+ million accounts. Actual liquidity varies significantly by market category.

Can you arbitrage across Polymarket, Kalshi, and DraftKings Predictions?

Yes. Price discrepancies exist across all three platforms for overlapping events due to different user bases, fee structures, and settlement mechanics. AI agents monitoring all three can identify cross-platform arbitrage opportunities. Execution requires accounts on each platform, managing different currencies (USDC for Polymarket vs. USD for Kalshi and DraftKings), and accounting for platform-specific fees. The largest persistent arbs tend to exist between Polymarket and the regulated platforms.

Is Polymarket legal in the US?

Polymarket officially geo-blocks US IP addresses and its terms of service restrict US residents from trading. The platform reached a settlement with the CFTC in 2022. However, because Polymarket operates on blockchain infrastructure, enforcement of geographic restrictions is technically challenging. US users should understand the legal risks before accessing the platform. For full regulatory clarity, Kalshi and DraftKings Predictions are the appropriate choices for US-based traders.

Which platform should I use to learn prediction market trading?

For US users, Kalshi offers the most structured learning environment with regulatory protection and a straightforward web interface. For international users, Polymarket provides easy onboarding with a crypto wallet and the deepest liquidity for practicing small trades. DraftKings Predictions is ideal for sports bettors who want a familiar environment to explore event contracts without learning a new platform.