Net Present Value and Internal Rate of Return Summarize the Returns for a Given Series of Cash Flows

NPV and IRR are wonderful at summarizing, in absolute and percentage terms, respectively, the returns for a given series of cash flows.

When cash flows are contractually determined, as in the case of a bond, and when all payments are received when due, IRR provides the precise rate of return to the investor while NPV describes the value of the investment at a given discount rate.

In the case of a bond, these calculations allow investors to quantify their returns under one set of assumptions, that is, that contractual payments are received when due.

These tools, however, are of no use in determining the likelihood that investors will actually receive all contractual payments and, in fact, achieve the projected returns.