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PrediX

Limit Order (CLOB)

Place a price and wait for a fill on the On-chain Order Book. You become a maker - and enjoy price improvement when matched.

When to use

Section titled “When to use”
  • ✅ You have a price view - e.g., buy YES @ $0.45 while the market is at $0.50, wait for the price to drop
  • ✅ Market making - place BUY and SELL orders simultaneously, earn the spread
  • ✅ Large trades where you want to avoid AMM slippage
  • ❌ Avoid when you need immediate execution - the order may never fill

How to Place a Limit Order

Section titled “How to Place a Limit Order”

  1. Step 1: Open the Limit Panel

    • Navigate to the market trading panel and select the Limit tab.

  2. Step 2: Configure Your Order

    • Side: Select YES.
    • Direction: Ensure Buy is selected.
    • Price: Enter your target price (e.g., buy YES @ $0.45).
    • Amount: Enter the total you wish to spend in USDC. PrediX will automatically calculate the equivalent amount of YES tokens (e.g., 100 USDC).

  3. Step 3: Preview your Order

    Before finalizing, verify the potential outcome:

    • If filled: You will receive approximately 222.22 YES tokens ($$ $100 / 0.45$ $$).
    • USDC Locked: 100 USDC will be held in escrow.

  4. Step 4: Execute and Confirm

    • Click Place Order.
    • Confirm the request in your wallet:

  5. Step 5: Monitor Your Order

    • Wait approximately 2 seconds for the transaction to process.
    • Once confirmed, your order is active. You can view the trade in your Portfolio under the History tab.

3 match types

Section titled “3 match types”

When someone places a market order or an opposing limit order, PrediX matches in one of three ways:

1. Complementary (most common) 
You:     BUY YES @ $0.45 — 100 USDC
Other:   SELL YES @ $0.44 — 50 USDC
Match:   Taker sells YES to you @ $0.44 (better than your limit)
         You receive 50 / 0.44 ≈ 113.64 YES
         Remaining 50 USDC stays locked
2. Mint (synthetic) 
You:     BUY YES @ $0.60
Other:   BUY NO @ $0.45
Total:   $1.05 ≥ $1
Action:  Diamond mints a YES+NO pair from $1 USDC
         YES goes to you, NO goes to the other party
         Spread $0.05 → protocol

Both parties receive the token they want; the protocol earns the spread.

3. Merge (synthetic) 
You:     SELL YES @ $0.40
Other:   SELL NO @ $0.45
Total:   $0.85 ≤ $1
Action:  Diamond collects YES + NO, burns them → $1 USDC
         Pays $0.40 to you + $0.45 to the other party
         Spread $0.15 → protocol

You do not need to calculate any of this — the matching engine optimizes automatically. The UI shows matchType in History.

Cancel an Order

Section titled “Cancel an Order”

  1. Step 1: Access Your Open Orders

    • Navigate to your Portfolio section.
    • Select the Open Orders tab to view all currently active limit orders.

  2. Step 2: Initiate Cancellation

    • Locate the specific order you wish to stop.
    • Click the Cancel button next to that order.

  3. Step 3: Confirm and Release Funds

    • Confirm the request in your wallet (e.g., biometric authentication for passkeys or a signature for EOA).
    • Once the transaction is signed, your locked USDC or tokens are automatically released back to your wallet in the same transaction.

Partial fill

Section titled “Partial fill”

Orders can be filled incrementally:

  • BUY YES @ $0.45, 100 USDC → someone takes 40 USDC → 60 USDC remains locked on the book.
  • Status: OPEN → PENDING (per indexer).
  • The remainder continues to wait for a match, or you can cancel it.

Limits

Section titled “Limits”
Value
Max open orders / user / market 50
Min size $1 USDC
Tick size $0.01
Stop-loss / OCO TBA - Phase 2

Prices must be multiples of $0.01: 0.01, 0.02, …, 0.99.

  • 0.455 will be rejected or rounded.
  • 99 ticks total, stored in a compressed bitmap in the PrediXExchange contract.
  • 0.00 and 1.00 are not supported - a price of certainty has no liquidity.