Layering is a type of market manipulation where a trader places multiple orders at different price levels to create the appearance of market depth, making it seem like there is more buying or selling interest than actually exists. This can include:

1. _Iceberg orders_: Breaking up large orders into smaller ones to hide true market impact.

2. _Price ladder attacks_: Placing multiple orders at incremental price levels to create a false market structure.

3. _Wash layering_: Placing matching buy and sell orders to create the appearance of market activity.

4. _Quote stuffing with layers_: Rapidly entering and canceling orders at multiple price levels to flood the market with quotes.

Layering can:

1. _Mislead other traders_: Creating a false sense of market depth and interest.

2. _Manipulate prices_: Influencing prices by creating a false sense of supply and demand.

3. _Disrupt market integrity_: Undermining trust in the market and its participants.

To detect and prevent layering, regulators and exchanges use:

1. _Trade surveillance_: Monitoring trading activity for suspicious patterns.

2. _Market monitoring_: Analyzing market data for unusual activity.

3. _Order book analysis_: Reviewing order book data to identify potential layering.

4. _Penalties and fines_: Imposing penalties and fines for engaging in layering.

5. _Improved market infrastructure_: Upgrading trading systems and technology to prevent technical issues.

Note: Layering is a prohibited practice in many markets, and traders engaging in such activities risk facing regulatory action, fines, and reputational damage.