Trading on Markets
Learn how to buy and sell outcome shares on AchMarket prediction markets.
Understanding Prediction Markets
How It Works
Prediction markets allow you to:
- Buy shares in an outcome (e.g., "Yes")
- Sell shares back to the market
- Profit if your outcome wins
Key Concepts
| Term | Definition |
|---|---|
| Share | A unit of an outcome |
| Cost | USDC paid to buy shares |
| Payout | USDC received when winning |
| Probability | Market's view of likelihood |
The Trading Interface
Layout
┌─────────────────────────────────────────────────────────┐
│ [Outcome A] [Outcome B] │
│ Selected: Outcome A (highlighted) │
├─────────────────────────────────────────────────────────┤
│ [Buy] [Sell] Slippage: [1% ▼] │
├─────────────────────────────────────────────────────────┤
│ │
│ Amount: [____________] USDC │
│ │
│ ───────────────────────────────────────────────────── │
│ │
│ Preview: │
│ • Shares: 50.0 Outcome A │
│ • Avg Price: $0.65 │
│ • Potential Payout: $76.92 (if wins) │
│ • Profit: $26.92 │
│ │
│ [Buy Outcome A] │
└────────────────────────────────────────────────── ───────┘
Outcome Selection
Click an outcome to select it:
- Only one can be selected at a time
- Selected outcome is highlighted
- Trading panel updates
Buying Shares
Step-by-Step
- Select Outcome - Click Yes or No (or custom)
- Choose Buy Tab - Click "Buy"
- Enter Amount - Type USDC to spend
- Review Preview - See estimated shares and payout
- Set Slippage - Choose tolerance (default 1%)
- Place Order - Click Buy button
- Confirm - Approve in wallet
- Wait - Transaction confirms on-chain
Understanding Preview
| Field | Description |
|---|---|
| Shares | You'll receive this many outcome shares |
| Avg Price | Average cost per share |
| Potential Payout | If this outcome wins |
| Profit | Payout minus your cost |
Example
Market: "Will BTC hit $100k?"
Current Probabilities:
- Yes: 65% ($0.65)
- No: 35% ($0.35)
You Buy:
- Amount: $100 USDC
- Shares: ~153.8 Yes shares
- Avg Price: $0.65
- Potential Payout: $153.84
- Profit: $53.84
Selling Shares
When to Sell
Sell shares when:
- You change your prediction
- You want to cut losses
- Market moves against you
- You need liquidity
Selling Process
- Select Outcome - Click the outcome you hold
- Choose Sell Tab - Click "Sell"
- Enter Shares - Type number of shares to sell
- Review Preview - See USDC you'll receive
- Place Order - Click Sell
- Confirm - Approve in wallet
Understanding Sell Preview
| Field | Description |
|---|---|
| Shares | Your shares being sold |
| Avg Price | Average price per share |
| You'll Receive | USDC from the sale |
Slippage Protection
What is Slippage?
Slippage is the difference between:
- Expected price when you submitted
- Actual price when executed
This happens because prices change with trading.
Setting Slippage
| Level | Use Case |
|---|---|
| 0.5% | Stable markets |
| 1% | Default, balanced |
| 2% | Moving markets |
| 5% | Very volatile |
Slippage in Action
You buy at $0.65 with 1% slippage:
- Expected: $0.65
- Max price: $0.6565
If execution price > $0.6565:
- Transaction reverts
- No shares purchased
Probability & Pricing
LMSR Mechanism
AchMarket uses LMSR (Logarithmic Market Scoring Rule):
- Dynamic pricing based on volume
- Price increases as more people buy
- Provides liquidity at all price levels
Price Movement
Initial: 50% Yes / 50% No
After $1,000 more Yes buys:
→ 65% Yes / 35% No (Yes price increases)
After $1,000 more No buys:
→ 35% Yes / 65% No (No price increases)
Portfolio Tracking
After Trading
Your position appears in Portfolio:
- See all outcomes you hold
- Track total deposited
- Claim winnings when resolved
Cancelled Markets
Full Refunds
If a market is cancelled:
- All traders can claim full refund
- Based on original deposit
- No fees collected
Resolved Markets
Winning Outcome
If you bought the winning outcome:
- See "Claim Winnings" button
- Click to redeem shares
- Receive pro-rata pool share
Losing Outcome
If you bought the losing outcome:
- Shares become worthless
- No redemption possible
- Loss = amount paid