Coordinated trading activity refers to the practice of multiple traders or accounts working together to manipulate market prices or volumes. This can include:

1. *Collusion*: Traders agreeing to buy or sell at specific prices or times to influence market conditions.

2. *Wash trading*: Trading with oneself to create the appearance of market activity or to manipulate prices.

3. *Pool trading*: A group of traders combining their resources to trade collectively.

4. *Front-running*: Traders using non-public information to trade ahead of others.

5. *Quote stuffing*: Rapidly entering and canceling orders to flood the market with quotes.

6. *Layering*: Placing multiple orders at different price levels to create the appearance of market depth.

7. *Spoofing*: Placing orders with no intention of executing them to manipulate prices.

Coordinated trading activity can be detected through:

1. *Trade surveillance*: Monitoring trading activity for suspicious patterns.

2. *Market monitoring*: Analyzing market data for unusual activity.

3. *Network analysis*: Identifying connections between traders and accounts.

4. *Behavioral analysis*: Identifying traders who consistently engage in suspicious activity.

5. *Machine learning algorithms*: Identifying patterns and anomalies in trading activity.

Regulators and exchanges use these methods to detect and prevent coordinated trading activity, maintaining fair and orderly markets.