Rho

Key Rho of function Price in Tradable configures the input so that any applicable interest rate risk is reported.

Web blog examples here and here

The price of the caller tradable generally depends on one or more Quotable or Valuation objects.
The entry here relates only to those objects that relate to interest rates.
When checked, the current array held by the key Risk Ref is extended with the above objects.
Also, the current array held by the key Risk Models is extended with corresponding default models.