What order would an investor use to protecta short position?

A stop buy order is used to protect a short position. This type of order instructs the broker to purchase a security if its price rises to a specified level, limiting the short seller's potential loss. It is triggered when the price reaches or surpasses the set stop price, helping the short seller exit the position to avoid unlimited losses.

Study Document References:

Volume 1, Chapter 9:Order Types and Protecting Short Positions, discussing how stop buy orders function for short sellers​​.