Alpha, which measures this value addition, is often taken as a metric to gauge fund performance. Investors who seek outperformance would be drawn towards funds running a higher alpha. But can investors always benefit from the pursuit of high alpha?

IMPORTANCE OF ALPHA

Simply told, alpha is the excess return delivered by a fund over its benchmark index. But more precisely , it is the excess return or value generated by a fund manager over the fund's expected return. This expected performance is based on the risk taken by the fund manager relative to the market, which is defined by beta.

Thus, a fund's alpha is derived from its underlying beta. A beta value of 1.5 indicates the fund would deliver 1.5% return for every 1% gain in the value of its underlying index.

Suppose a fund with a beta of 1.5 delivers a return of 18% over a certain period while its underlying benchmark index posts 12% returns. Given the beta, the fund manager would be expected to deliver a return of 18% (12%*1. 5). So, in this case, the fund manager has actually failed to generate alpha even though the fund has delivered 6% excess return over its benchmark.

If the fund delivered a return of 20% for the same underlying risk, the alpha generated would be 2%. Which implies that alpha represents the fund manager's expertise in stock selection or portfolio building. Most top-performing funds over longer time periods boast of a high alpha. In most cases, if a fund has generated high alpha in the past, it is likely to generate the same in the future too. Thus, it would bode well for investors to pay attention to a fund's alpha when selecting equity funds.

However, experts insist that consistency in delivering alpha is critical. Certain funds are good at delivering alpha only during a market uptrend.The fund should show consistency in generating alpha across various time frames and market cycles. Alpha can be a good indicator of a fund manager's ability provided there is consistency in the philosophy and processes driving the portfolio selection. Also, bear in mind that extent of alpha varies between fund categories. Typically, mid-cap oriented equity funds are able to deliver higher alpha than large-cap oriented ones. While mid-cap funds can comfortably clock alpha in excess of 8-10%, alpha in large-cap funds is typically lower.

WHERE ALPHA MAY NOT WORK

Alpha as a metric has a few shortcomings, which can make its extensive use counter-productive. First, alpha depends on the underlying benchmark index for the fund. Even though we may measure it in absolute terms, alpha is actually a relative measure dependent on market proxy . This can have several implications.

It can prevent effective comparison between funds, even within the same fund category . Since different equity funds within the same category also tend to be benchmarked against different indices, the alpha statistic will measure outperformance relative to that benchmark. You can end up comparing apples to oranges.

Another gripe analysts have with using alpha is that it is ignorant of the risk-adjusted performance. While it measures excess return given the level of market risk, it makes no adjustment for the risk involved in delivering that additional performance. As such, experts insist that alpha should not be used in isolation while picking funds.It should be supplemented with other metrics to really gain true understanding of the performance of the fund. Investors give equal importance to the underlying risk.  Go with a fund offering healthy alpha but lower beta.

Birla Sun Life Pure Value, for example, has delivered a healthy alpha of 10% over the past five years with a beta of 1.06. Its peer in the same category , BNP Paribas Midcap Fund has delivered similar return although at a lower beta of 0.83. Belapurkar says just looking at alpha does not provide the entire picture. Investors need to dissect the number further to see where the alpha is actually coming from. If it is due to a high risk taken by the fund manager, then it could be a red flag. Investors need to consider other risk factors apart from beta.