How it works:
You set a stop price.
When the stock reaches that price, your order activates.
It converts into a market order.
Common use:
Limiting potential losses
Protecting gains
Important:
Once triggered, it becomes a market order, so execution price is not guaranteed.
Example:
You own a stock at $50.
You set a stop at $45.
If the stock hits $45, your order activates and sells at the next available price — which could be slightly below $45 in fast markets.