Why changes to volatility values in Market Data do not trigger automatic recalculation of P&L value for FFA Options?

This article explains the reason why the P&L value for FFA options trades does not change ,when there is a change in volatility values.

1.Go to Market Data - Trading Profile and observe the model used by the client
In this specific case it is Turnbull Wakeman (1991)

2.Navigate to Market Data and select the route (example 5TC_C).

Change the volatility sign for March 2027 from negative to positive. Example: From -75.75 to +75.75

3.Navigate to Trade Details list and view the trade in question.

Observe that the P&L Value has not changed

The trade continues to display the same P&L values with no recalculation occurring, despite the volatility sign in the underlying market data being changed.

The Turnbull Wakeman model does not consider a change of the sign. According to this model, whether there is a positive (+75.75) or a negative value (-75.75), the result P&L value in the Trade Details Drilldown will stay the same.

Note! According to the model, the trigger of a change in the P&L value will occur when the value is changed. For example: change from 75.75 to 60.0