Crypto Wallet (MetaMask)
Definition
A Crypto Wallet is your on-chain account used to hold USDC/outcome tokens and sign transactions (e.g., MetaMask).
What is a Crypto Wallet?
A crypto wallet is software that:
- Stores your private keys
- Displays your balances
- Signs transactions
- Interacts with blockchain apps (dApps)
Think of it as a key to your blockchain account, not a storage location.
Popular Wallets for Polymarket
MetaMask (Most Common)
- Browser extension
- Mobile app
- Easy to use
- Wide compatibility
- Download: metamask.io
Other Compatible Wallets
- Coinbase Wallet: User-friendly
- WalletConnect: Mobile-first
- Rabby: Advanced features
- Rainbow: iOS/Android
Setting Up MetaMask
Installation
- Download from metamask.io
- Install browser extension
- Create new wallet
- Save seed phrase (CRITICAL!)
- Set password
Adding Polygon Network
Polymarket uses Polygon, not Ethereum mainnet:
- Open MetaMask
- Click network dropdown
- Add "Polygon Mainnet"
- RPC URL: https://polygon-rpc.com
- Chain ID: 137
- Symbol: MATIC
Connecting to Polymarket
- Go to polymarket.com
- Click "Connect Wallet"
- Choose MetaMask
- Approve connection
- Start trading
Security Best Practices
Seed Phrase
- Never share with anyone
- Write it down physically
- Store securely (not digitally)
- Never enter on suspicious websites
Password
- Use strong, unique password
- Enable browser password manager
- Don't reuse passwords
Phishing Protection
- Verify URLs (polymarket.com)
- Don't click suspicious links
- Check transaction details before signing
- Enable MetaMask security alerts
Hardware Wallet
For large amounts, consider:
- Ledger
- Trezor
- Connect via MetaMask
Using Your Wallet
Viewing Balances
- USDC: Your trading currency
- Outcome tokens: Your market positions
- MATIC: For gas fees (small amounts)
Making Transactions
- Initiate on Polymarket (buy/sell)
- Review in MetaMask popup
- Confirm gas fee and amount
- Sign transaction
- Wait for confirmation (5-30 seconds)
Managing Gas
- Keep small amount of MATIC (~$1-5)
- Needed to pay transaction fees
- Automatically deducted
- Get from exchanges or bridges
Wallet Address
Your wallet address is public:
- Format: 0x1234...5678 (42 characters)
- Like email: Safe to share for receiving
- On Polygon: Same address as Ethereum
- View on explorer: polygonscan.com
Common Issues
"Insufficient Funds"
- Need MATIC for gas fees
- Get from faucet or exchange
"Wrong Network"
- Switch to Polygon in MetaMask
- Check network dropdown
"Transaction Failed"
- Increase gas limit
- Check USDC balance
- Try again in few minutes
"Cannot Connect"
- Refresh page
- Clear browser cache
- Try different browser
- Disable conflicting extensions
Mobile Usage
MetaMask Mobile
- iOS and Android apps
- Built-in browser
- WalletConnect support
- Face/Touch ID
Using Polymarket Mobile
- Open MetaMask app
- Go to Browser tab
- Visit polymarket.com
- Trade normally