What Is the Options Greek “Rho” and How Is It Measured?

Rho is the options Greek that measures the sensitivity of an option's price to a 1% change in the risk-free interest rate. It is a derivative of the option pricing model.

Rho is positive for call options (calls increase in value as rates rise) and negative for put options (puts decrease in value as rates rise). It is generally considered the least important Greek for short-term options.