Polymarket vs Kalshi June 2025: Which Platform Wins?
Polymarket and Kalshi are the two dominant prediction market platforms in June 2025, but they serve fundamentally different types of traders. Polymarket operates as a decentralized, crypto-native platform with massive liquidity on political and global events, while Kalshi is a CFTC-regulated exchange that lets Americans trade legally on real-world outcomes. Choosing between them comes down to your risk tolerance, trading style, regulatory comfort, and which markets matter most to you.
Why June 2025 Is a Critical Month for Prediction Markets
June 2025 is shaping up to be one of the most active months for prediction markets in recent memory. You've got geopolitical tension rippling through energy and currency markets, active sports seasons, ongoing Congressional hearings about AI regulation, and macroeconomic data releases that traders are pricing in real time.
Both Polymarket and Kalshi are seeing surges in volume. Polymarket reportedly processed over $500 million in monthly volume in Q1 2025, while Kalshi crossed $1 billion in cumulative trade volume earlier this year — a milestone that signals the sector's rapid maturation. Understanding how each platform handles this surge, and what that means for your trades, is more important than ever.
If you're new to the space, the beginner's guide to political prediction markets is an excellent starting point before diving into platform comparisons.
Platform Overviews: What Each One Actually Is
Polymarket
Polymarket is a decentralized prediction market built on the Polygon blockchain. It uses USDC as its primary currency and operates through smart contracts, meaning no single entity controls your funds. Anyone with a crypto wallet — in most jurisdictions — can participate.
Key characteristics:
- Decentralized and permissionless — no KYC required in most cases
- Peer-to-peer liquidity powered by automated market makers (AMMs)
- Markets on politics, crypto, sports, science, pop culture, and more
- No US users officially (geo-restricted, though widely circumvented)
- Resolves via the UMA oracle system
Kalshi
Kalshi is a federally regulated Designated Contract Market (DCM) under the CFTC. It operates like a traditional financial exchange, which means US residents can use it legally and your funds are held in segregated accounts.
Key characteristics:
- CFTC-regulated — legally accessible to US traders
- Trades in US dollars (no crypto required)
- Markets on economics, politics, weather, interest rates, and more
- Requires full KYC verification
- Resolves based on official government or authoritative data sources
Head-to-Head Comparison Table
| Feature | Polymarket | Kalshi |
|---|---|---|
| Regulation | Decentralized / unregulated | CFTC-regulated DCM |
| US Access | Geo-restricted (blocked) | Fully legal for US residents |
| Currency | USDC (crypto) | US Dollars |
| KYC Required | Minimal / none | Full KYC required |
| Market Volume (June 2025) | ~$500M+ monthly | Growing, $1B+ cumulative |
| Market Types | Politics, crypto, sports, pop culture | Economics, politics, weather, rates |
| Fees | ~2% maker/taker spread | ~2–3% per side (varies) |
| Liquidity Depth | Very high on major markets | Moderate, improving rapidly |
| Wallet Required | Yes (MetaMask, etc.) | No — standard bank/card |
| Withdrawal Speed | Near-instant (on-chain) | 1–5 business days |
| API Access | Yes (public) | Yes (institutional focus) |
| Mobile App | Web-only (mobile browser) | Native iOS and Android app |
Fee Structures Compared: Where Does Your Money Go?
Fees are often the silent killer of prediction market profits. Both platforms have nuanced fee structures worth understanding before you place your first trade in June.
Polymarket Fees
Polymarket uses a spread-based model rather than explicit commissions. When you buy shares in a market, the difference between the bid and ask price represents the platform's take. On highly liquid markets (like major US election questions), this spread can be as tight as 1–2 cents per share. On smaller markets, you might see spreads of 5–10 cents, which translates to significant cost on large positions.
There are no deposit or withdrawal fees on the USDC side, but you'll pay Polygon network gas fees, which are typically less than $0.01 per transaction in June 2025.
Kalshi Fees
Kalshi charges explicit trading fees that vary by market type and your account tier. Standard retail traders typically pay around 2–3% of the contract value per trade. Kalshi has been rolling out volume-based discounts, so high-frequency traders can negotiate better rates.
Deposits via ACH are free; wire transfers may carry a small fee. Withdrawals typically take 1–5 business days, which matters if you're trying to move capital quickly between markets.
Bottom line: For small traders doing high volume, Kalshi's explicit fees can compound faster. For large trades on liquid Polymarket markets, spreads are competitive. Always calculate your all-in cost before executing.
Market Selection: Where Each Platform Dominates
This is arguably the most important factor for most traders. The best platform is the one that covers your markets.
Where Polymarket Leads
Polymarket dominates in:
- Crypto and Web3 markets (ETH price targets, protocol launches, token unlocks)
- Global political events (elections outside the US, geopolitical outcomes)
- Sports and entertainment (Oscar winners, FIFA outcomes, NBA championship odds)
- Niche and emerging markets (AI model releases, scientific milestones)
For example, Polymarket had active markets on the 2024 Indian and EU elections months before results, with hundreds of thousands in liquidity. If you're interested in automating your predictions around scheduled events, Polymarket's breadth of markets and API access makes it a natural fit.
Where Kalshi Leads
Kalshi dominates in:
- Economic data releases (CPI, Fed rate decisions, unemployment numbers)
- US political and legislative events
- Weather and climate outcomes
- Interest rate and Treasury markets
The platform's regulatory standing means it can legally offer markets that Polymarket cannot touch in the US market. If you're interested in geopolitical risk analysis with structured order types, Kalshi's limit order infrastructure makes it a strong contender.
Liquidity and Execution Quality in June 2025
Liquidity isn't just about volume — it's about how easily you can enter and exit positions at the price you expect.
Polymarket Liquidity
Polymarket's liquidity is heavily concentrated. The top 10 markets by volume typically account for over 60% of total daily trading activity. If you're trading headline political events or major crypto questions, you'll find tight spreads and deep order books. But venture into mid-tier markets and you may struggle to fill large orders without moving the market against yourself.
Kalshi Liquidity
Kalshi's liquidity is more evenly distributed across its market categories, partly because institutional market makers are contracted to provide it. However, total depth is lower than Polymarket's top markets. The Fed rate decision markets on Kalshi are particularly liquid in June 2025 given current macroeconomic uncertainty.
For traders exploring advanced political prediction market strategy, understanding where liquidity concentrates on each platform is essential to sizing positions correctly.
Regulatory Risk: The Elephant in the Room
This is where the platforms diverge most sharply.
Kalshi's regulatory moat is significant. The CFTC designation means Kalshi fought and won the right to offer these markets legally. This regulatory clarity protects both the platform and its users from sudden enforcement actions that could freeze funds or shut down operations.
Polymarket's regulatory status remains ambiguous for US users. The platform geo-blocks American IP addresses, but enforcement risk hasn't disappeared. In early 2024, Polymarket paid a $1.4 million settlement with the CFTC for operating an unregistered facility — a reminder that regulators are watching.
For US-based traders, this risk calculus is clear: Kalshi is the legally compliant choice. For international traders where Polymarket is accessible, the decentralized architecture reduces — but doesn't eliminate — risk.
If you're thinking about the tax implications of trading on either platform, the tax guide for AI agents in prediction markets covers some important nuances that apply broadly to prediction market income.
How to Get Started on Each Platform
Getting Started on Polymarket
- Install a Web3 wallet (MetaMask or Coinbase Wallet recommended)
- Purchase USDC on a crypto exchange (Coinbase, Kraken, etc.)
- Bridge USDC to Polygon using the Polygon bridge or a supported on-ramp
- Connect your wallet to Polymarket.com
- Browse markets, review resolution criteria carefully
- Place your trade and monitor via the Polymarket dashboard or API
- Withdraw USDC back to your exchange when you want to cash out
Getting Started on Kalshi
- Create an account at Kalshi.com
- Complete KYC verification (government ID required — usually takes minutes)
- Link your bank account or deposit via debit card
- Fund your account with USD (ACH typically free)
- Browse available markets by category
- Place limit or market orders on your chosen contracts
- Withdraw to your bank when ready (1–5 business days)
Strategic Considerations: Which Platform Fits Your Style?
The right platform depends on your trading approach:
- Arbitrageurs: Opportunities exist between both platforms on overlapping markets. For a detailed breakdown of how to exploit these gaps, see this guide on prediction market arbitrage strategies.
- US-based retail traders: Kalshi is your legally safe home base. Start there.
- International crypto-native traders: Polymarket's liquidity and market variety are hard to beat.
- Algorithmic traders: Both offer APIs, but Polymarket's public API and open smart contract structure give developers more flexibility. Tools like PredictEngine are built to work across both platforms, giving you unified data and execution signals.
- Hedgers and portfolio managers: Kalshi's economic markets (CPI, Fed rates) are genuinely useful for smart portfolio hedging in ways that Polymarket's markets less directly support.
Frequently Asked Questions
Is Polymarket legal for US traders?
Polymarket is geo-blocked for US users and is not legally available to American traders without circumventing the restriction. The platform settled with the CFTC in 2024 for operating an unregistered facility, and US traders who access it via VPN do so at their own regulatory and financial risk.
Is Kalshi safe to use in June 2025?
Yes — Kalshi is a CFTC-regulated exchange, which means it meets federal compliance standards and holds customer funds in segregated accounts. It is one of the safest prediction market platforms for US traders, with legal standing confirmed by a court ruling in 2024 that upheld its right to offer event contracts.
Which platform has better liquidity, Polymarket or Kalshi?
Polymarket has higher raw liquidity on its top markets, with monthly volumes exceeding $500 million. Kalshi's liquidity is more evenly distributed and backed by contracted market makers, making it more reliable for mid-tier economic and political markets. The best choice depends on which specific markets you want to trade.
Can I use bots or automated trading on either platform?
Both platforms allow API access, and automated trading is possible on each. Polymarket's open smart contract architecture gives developers more flexibility, while Kalshi's API is more structured and suitable for institutional-style automation. Platforms like PredictEngine offer pre-built tools to automate and optimize your trading signals across prediction markets.
What are the fees on Polymarket vs Kalshi?
Polymarket charges no explicit fees but earns revenue through bid-ask spreads, which range from 1–10% depending on market liquidity. Kalshi charges explicit trading fees of approximately 2–3% per side, with volume-based discounts available. Always calculate total round-trip cost before sizing a position on either platform.
Which platform is better for political prediction markets?
It depends on your focus. Polymarket excels at global political markets, including international elections and geopolitical events. Kalshi excels at US political and legislative markets, with CFTC-compliant contracts that allow legal trading for American residents. Serious political traders often monitor both for the best odds and liquidity.
The Bottom Line: Polymarket vs Kalshi in June 2025
There's no single winner in the Polymarket vs Kalshi debate — the right answer depends entirely on who you are and what you want to trade. If you're a US-based trader who values regulatory protection and wants to trade economic data releases and domestic political events, Kalshi is your platform. If you're an international crypto-native trader looking for massive liquidity across global events, pop culture, and crypto markets, Polymarket is the stronger choice.
For serious traders, the smartest move in June 2025 is to understand both platforms and leverage each for what it does best — including spotting arbitrage opportunities when both platforms cover the same event at different odds.
PredictEngine is built for exactly this kind of multi-platform, data-driven prediction market trading. Whether you're analyzing political outcomes, hedging economic risk, or automating your strategy with AI-powered signals, PredictEngine gives you the edge you need to trade smarter on both Polymarket and Kalshi. Sign up today and start your free trial to see how unified prediction market intelligence can transform your approach this June.
Run your own quant desk
Felix lets you research, backtest and run automated trading strategies, with risk controls built in.
Try Felix