What is 4rho?
4rho is a non-custodial prediction-market exchange. You trade on the outcomes of real-world events — sports, elections, crypto prices, and more — by buying and selling outcome tokens that pay $1 each if your side wins and $0 if it does not.
Non-custodial — your money is your money
Your USDC stays in a smart contract on the Polygon blockchain. Only your wallet can move it. 4rho cannot freeze your balance, deny a withdrawal, or step in front of a trade you've signed.
The smart contract addresses are public and can be audited at any time:
| Chain ID | — |
| Exchange | — |
| Market factory | — |
| Conditional tokens (CTF) | — |
| USDC (collateral) | — |
| Fee sweeper | — |
Loading current contract addresses…
How trading works
Every market has two sides — YES and NO. Each side is a token that pays out $1 if it wins and $0 if it loses. The price you pay between $0 and $1 is the market's estimate of how likely the outcome is.
If you buy YES at $0.42 and YES wins, every share returns $1. If NO wins, your shares are worth $0.
Orders match through an order book: a maker posts a price, a taker accepts it, and the trade settles on-chain. Fees are fixed, transparent, and shown before you sign:
| Role | Fee | Notes |
|---|---|---|
| Maker | 0% | You posted a resting order someone else accepted. |
| Taker | 0.5% | You accepted an existing resting order. |
Some accounts and markets have negotiated rates; your effective rate is shown when you place an order.
What you'll need to get started
- An email address, passkey, or an existing wallet (MetaMask, Coinbase Wallet, Rainbow, or anything WalletConnect-compatible).
- Some USDC on Polygon. You can buy it with a card via Coinbase from inside 4rho, or bring it from another exchange.
That's it. There's no separate platform balance, no minimum deposit, no closed beta.
Where to next
- New here? Read How to start trading.
- Curious about the mechanics? Try Prediction markets, in plain English.
- Building a bot? See the API reference.