The Challenges of Interpreting Internal Rate of Return (IRR)

The Internal Rate of Return (IRR) is one of the most universal return concepts, and rightly so because of its effectiveness in interpreting returns from an investment. However, it is also one of the most difficult concepts to wrap your head around. In my personal opinion, the difficulty arises primarily due to the understanding of the fundamental underpinnings of the definition. It is not my intention to turn this discussion into a technical one; since the objective is to demystify, I will break it down for simpler understanding.

Firstly, the IRR is better understood when used to compare returns from two or more investments. The decision rule is rather simple – the higher the IRR, the better. The confusion arises when investors look at the IRR in isolation i.e. an investment yields a 20% IRR so what does that mean? The answer is a complicated one and often leads to more questions.

Secondly, the IRR is a multi-period return measure. What this means is that when investors would like to compare investments that span different time periods, IRR becomes the best tool for this purpose. For instance, investment A returns 20% in X years whereas investment B returns 25% in Y years. The question as to which investment performs better is best answered by the IRR.

Thirdly, the IRR works best when investments have conventional cash flows patterns i.e. a negative cash flow followed by multiple positive cash flows. Any variations herein are bound to be detrimental to the IRR calculation. For instance, you buy a stock (negative cash flow) and receive dividends (positive cash flow) during the holding period. The IRR works well in this scenario. However, if you short a stock (positive cash flow) and buy another one (negative cash flow) with the proceeds and finally square of the transaction (positive or negative cash flow) later on, the IRR may not necessarily yield desired results.

Lastly, due to its very definition, in some instances an investment may have no IRR at all or at least one that can be determined! Obviously, in such instances, the IRR is of no use and creates confusion in the mind of the investor. Therefore, the challenges in interpreting IRR arise when investors use the IRR for purposes other than those mentioned above.

Although this list is by no means exhaustive, it captures the salient features of the IRR. Hope this piece has helped simplify the concept and gives you confidence to seamlessly compare investments using IRR.

Vinay Basavaraj

Vinay boasts of a decade of experience working in both large and small organizations. His roles have ranged from sales to operations and even a stint in academia. He currently manages affairs in capital markets in Capital Float.