What must happen to limit orders that are not executed immediately?

The correct answer highlights an important aspect of how limit orders work in the context of trading regulations. When limit orders are placed and not executed immediately, they typically must be made public unless the trader specifies a particular condition that allows for them to remain private or confidential. This requirement is in place to ensure transparency in the market, allowing other participants to be aware of pending orders that may affect pricing and trading strategies.

This transparency helps maintain an orderly market by ensuring that all traders have access to the same information, which is crucial for fair trading practices. It also encourages a more competitive environment, as other market participants can see where buy and sell interest lies.

The other options related to how limit orders that are not executed immediately are treated do not align with the established regulatory framework regarding order handling. For example, ignoring an order would disrupt the integrity of the trading process, while automatic cancellation or rendering the order void after a set period could detract from a trader's ability to wait for favorable market conditions. Overall, the requirement for public disclosure, unless specified otherwise, supports market efficiency and fairness.