# Orders

## Placing Orders

Users can place orders into the protocol through the [Ithaca App](https://docs.ithacaprotocol.io/docs/ithaca-app). An SDK is available for advanced users.

All valid orders placed during an auction's Order Submission Period get included in that upcoming auction.

## Order Types

All orders are required to be limit orders given the auction format. The protocol does not allow for market orders to be submitted.

Basic or multi-leg [conditional orders](#conditional-orders) may be submitted. 

An order stays live in the order book until it is canceled or expiry.  

## Conditional Orders

The Ithaca protocol allows for the submission of conditional orders of two or more legs. Each leg of a conditional order enters the matching engine as a separate order. Legs of a conditional order can either be BUY or SELL orders. The order legs can be for any product tradable on the Ithaca platform. 

A conditional order can either be fully executed with all the legs fully executed; or it can be partially executed with all its legs executed at the same pro-rata volume fraction.

A conditional order has one net limit price / premium across all legs. A leg with a buy order is counted positively while a leg with a sell order is to be counted negatively towards the net limit price. Therefore, the net limit price of a conditional order represents the price of a normalized quantity of 1 unit.

#### Reduced Execution Risk and Collateral Optimization

Conditional orders eliminate the execution risk between different legs of a trading strategy. There is a further collateral optimization benefit for conditional orders compared to what would be required for the corresponding orders if submitted as independent orders. 

The Ithaca Protocol runs collateral optimization on a conditional order as a package and only the optimized collateral is needed at order entry.

For examples of potential conditional orders, please refer to [Ithaca App Stories](https://docs.ithacaprotocol.io/docs/ithaca-app/trading/stories).