Net Present Value (NPV) The NPV function calculates the cumulative present values of a series of cash flows all at once. NPV = t = 1nCFt(1 + I)t An investment with a positive NPV adds value, whereas an investment with a negative NPV loses value. Assuming a 9% interest rate, what is the NPV of the cash flow stream shown above? NPV = Assuming a new 7% interest rate, what is the NPV of the cash flow stream shown above? NPV = This example demonstrates the relationship between interest rates and present values. As interest rates increase, the present value (PV), or net present value (NPV), will