> ## Documentation Index
> Fetch the complete documentation index at: https://docs.jua.exchange/llms.txt
> Use this file to discover all available pages before exploring further.
# House Orders vs. Limit Orders: Jua Trading Engines
> Understand the difference between house (market) orders and CLOB limit orders on Jua Predictions, and learn when to use each trading engine.
Every Jua Predictions market runs two trading engines side by side: the house engine (an automated market maker) and the CLOB engine (a central limit order book). You can use either one on any open market — they coexist on the same market page, and choosing between them is as simple as switching a tab in the trading panel.
## House Orders vs. CLOB Limit Orders
The house engine is an automated market maker (AMM) that acts as your counterparty on every trade. There is always liquidity available — you never need to wait for another trader to match your order.
**How it works:**
* You choose YES or NO and enter a USDC amount.
* The house quotes you a per-share price based on current supply and demand.
* Your order fills instantly at that price — no waiting, no partial fills.
* After your trade, the price adjusts slightly in the direction of demand, so larger orders move the price more than smaller ones.
**Best for:**
* Traders who want certainty of execution over price precision.
* Smaller positions where the price impact is minimal.
* Fast-moving markets where waiting for a limit order to fill carries event risk.
The CLOB engine is a peer-to-peer central limit order book. Your order is matched against orders placed by other traders — the house is not your counterparty.
**How it works:**
* You choose YES or NO, set a price (0–1 USDC per share), and specify a share quantity.
* Your order is added to the public order book at your chosen price level.
* It fills when another trader places a matching order on the opposite side.
* You may receive a **partial fill** if only some of your shares can be matched at your price.
* Unmatched portions remain open in the order book until filled or cancelled.
**Best for:**
* Traders who want to control the price they pay or receive.
* Larger positions where executing at a specific price significantly affects returns.
* Patient traders comfortable waiting for the market to come to their price.
## Choosing an Engine
Both engines are valid tools — the right choice depends on what matters more to you for a given trade.
**Use the house engine when:**
* You want your trade to execute immediately without any risk of non-fill.
* You're placing a smaller position and the slight price impact is acceptable.
* The event you're trading on is imminent and execution speed matters more than shaving a few cents off the price.
**Use the CLOB engine when:**
* You have a specific price target and you're willing to wait for the market to reach it.
* You're trading a larger size and want to avoid the price impact that a large house order would cause.
* You see a gap in the order book at a favourable price level and want to provide liquidity there.
## Order States
A CLOB limit order moves through several states during its lifetime. House orders skip directly to **Filled** since they execute instantly.
| State | What it means |
| -------------------- | -------------------------------------------------------------------------------------- |
| **Pending** | The order is live in the order book and waiting for a matching counterparty order |
| **Partially Filled** | Some shares have been matched; the remainder is still open in the order book |
| **Filled** | All shares have been matched; the order is complete and no longer in the book |
| **Cancelled** | You cancelled the order; all unfilled shares are removed and locked funds are released |
While a limit order is open (Pending or Partially Filled), the USDC required to cover the unfilled portion is locked and unavailable for other trades. Cancelling the order releases those funds back to your available balance immediately.