Clients wishing to see forex (IDEALPRO) market data in a more detailed way can now control the order book display mode via the Global Configuration. In order to access this feature you must use TWS release 944.2b or higher. The display mode selection allows the order book to be viewed either as:

• Rounded prices (default): market data is rounded out to the next 0.5 pip. This is identical to the current display functionality for the IB trading platforms. This setting provides a more stable visible quote and a larger ‘top-of-book’ size since it includes the available size at multiple price levels up to the rounded price.
• Unrounded prices: market data is visible in 0.1 pip increments. This allows you to see prices in a more granular fashion, but the displayed values will change more rapidly and the sizes for the top-of-book may appear to be smaller.

It is important to understand that either display mode accesses the same IDEALPRO order book. Order submission will still be in 0.5 pip increments and orders submitted in either display mode will execute in exactly the same way. As in the past (and currently), in cases where the order book has prices at better than your order’s limit price, you will receive the full price improvement.