Specifically, is the probability that the call will be exercised provided one assumes that the asset drift is the risk-free rate. , however, does not lend itself to a simple probability interpretation. is correctly interpreted as the present value, using the risk-free interest rate, of the expected asset price at expiration, given that the asset price at expiration is above the exercise price. For related discussion and graphical representation see Datar–Mathews method for real option valuation.
Specifically is the probability that the call will be exercised provided one assumes that the asset drift is the risk-free rate  however does not lend itself to a simple probability interpretation is correctly interpreted as the present value using the risk-free interest rate of the expected asset price at expiration given that the asset price at expiration is above the exercise price For related discussion and graphical representation see Datar–Mathews method for real option valuation