A stop-loss is an order placed with a broker to buy or sell a security when it reaches a certain price. It's designed to limit an investor's loss on a position in a security.

### Importance of Stop-Loss:

1. **Risk Management**: Stop-loss orders help to limit losses by setting a predefined exit point, thus managing the risk on any given trade.

2. **Emotion Control**: They prevent emotional decision-making by automatically triggering the sale of a security when it reaches the specified price, thereby helping investors stick to their trading plan.

3. **Protection in Volatile Markets**: In highly volatile markets, a stop-loss order can help protect against significant losses during sudden market movements.

4. **Time Management**: It allows investors to continue with their daily activities without having to constantly monitor their positions, as the stop-loss order will automatically execute when the conditions are met.

5. **Discipline**: Using stop-loss orders instills a disciplined approach to investing, as it forces investors to set clear exit strategies.

Overall, stop-loss orders are a vital tool for maintaining control over investments and minimizing potential losses.