What special provision must be made regarding algo orders and quotes in the trading system?

Algo orders and quotes must be marked in the trading system to ensure transparency and facilitate better understanding of the nature of trading strategies being employed. By marking algo orders, market participants can identify that a particular order or quote is generated by an algorithm, which can have implications for liquidity, volatility, and market dynamics. This identification is crucial for both regulatory purposes and for market participants who seek to understand and analyze order flow.

Marking algo orders also enables the trading system to apply specific rules and protections that may be necessary to prevent market manipulation and ensure fair trading practices. It helps in maintaining orderly trading and allows for better monitoring and reporting of trading activity, ensuring compliance with established trading regulations. Other provisions such as execution during auctions, volume limits, or double-entry for validation do not specifically address the importance of identification and transparency of algorithmic trading within the market infrastructure.