The key objective behind the Expected Return Range Framework is to highlight the volatility of the markets, especially on the negative side. And hence guide investors and potential clients of deciding their asset allocation very carefully. We have used the theoretical framework of Normal Distribution for this exercise. The expected returns mentioned by us at the outset is just an estimate and we do not guarantee the same. In fact, we believe that returns are an uncontrollable factor, and our key role is to mitigate the risks you face in achieving your financial goals. Hence when you invest your hard-earned money into various asset classes and instruments, you should be made aware of all kinds of scenarios. As what you do not want to do is to abandon the plan in panic. We have computed the return range at 95% confidence level (refer to the Notes on the page & the Investopedia link). The return range will broaden (both negative & positive) if we were to compute at 99% confidence level. Even at 99% confidence levels, the tail risk or what has come to be known as Black Swan events do not get captured.
To summarise, our objective is only to caution you so that you invest as per your comfort levels. After all, you have worked so hard to build your nest of savings.