What does each status mean at different stages of a limit order?

"Monitoring" means that your request is still within your specified time period, and the market rate has not reached your target rate yet.

"Target rate detected. Processing" means that your request has reached your specified rate and is currently being processed. The process will be completed within 1-2 business days.

"Expired" means that your request has exceeded your specified time limit and could not be fulfilled within the specified rate range. The funds will be automatically returned to your balance.