Alpha and Beta in Mutual Funds, Explained Simply

Beta compares a fund movement with its benchmark index. A beta of about one means the fund has tended to move roughly in line with the benchmark.

A beta above one means the fund has usually swung more: rising more in good times and falling more in bad. A beta below one means it has usually swung less.

Our page on the benchmark explains what a fund is compared against.

Imagine the benchmark rises by a certain amount. A fund with a beta well above one would, on average, have risen a bit more. A fund with a beta well below one would have risen a bit less.

When the benchmark falls, the same pattern tends to repeat in the other direction. Beta is about the size of the swings, not whether the fund is good or bad.

Alpha tries to answer a simple question: after allowing for how risky the fund was, did it do better or worse than expected?

A positive alpha means the fund delivered more than its risk level would suggest. A negative alpha means it delivered less. Many people see alpha as a rough measure of the fund manager skill.

A fund can show strong returns simply because it took more risk, with a high beta, in a rising market. That is not the same as skill.

Alpha separates the two. A fund with good returns and positive alpha has done well even after accounting for its risk. A fund with good returns but zero or negative alpha may just have been riding a strong market.

Many actively managed funds show negative alpha over some periods, especially after costs. Beating a benchmark consistently is genuinely hard.

That is one reason some investors prefer index funds: they accept the market return at low cost instead of paying for a chance at positive alpha. Our page on active versus passive funds explains this choice.

Many fund fact sheets show beta, and some show alpha, in a section on risk measures. Comparison websites often show both.

Check the period they cover, usually three years, because a different period gives different numbers. Our page on the fact sheet explains where to look.

If big swings make you nervous, a fund with a lower beta may be easier to hold through falls. If you have a long horizon and can stay calm, a higher beta may be acceptable.

The right beta is the one you can live with without selling in a panic. Our page on risk and volatility explains why staying invested matters so much.

Alpha is calculated from past returns. A fund that showed positive alpha over the last three years may not repeat it. Fund managers change, markets change, and strategies that worked can stop working.

Treat alpha as one useful clue about past management, not as a promise. Our page on rolling returns shows a better way to judge consistency over time.

Beta is most useful for equity funds. For debt funds, interest rate sensitivity is better measured by duration, as our page on YTM and modified duration explains.

For hybrid funds, beta can be lower than one because of the debt portion, which is part of why they tend to swing less.

An index fund aims to match its index, not beat it. So its alpha should be close to zero, slightly negative after costs. Its beta should be close to one.

That is exactly what you want from an index fund. Our pages on index funds and tracking error explain how to judge them.

Some fact sheets also show R-squared, which tells you how closely a fund movements match its benchmark. A high figure means beta and alpha are more meaningful, because the fund really behaves like its benchmark.

A small cap fund will naturally have a different beta from a large cap fund. Comparing alpha or beta across categories gives a misleading picture.

Compare funds within the same category, over the same period, using the same benchmark. Our page on SEBI fund categories explains the groups.

Alpha and beta sit next to other risk measures such as standard deviation and the Sharpe ratio. Each tells a different part of the story.

Our page on Sharpe ratio and standard deviation explains those, and our page on the portfolio turnover ratio covers trading activity.

• Shortlist funds in the category you need.
• Compare returns against the benchmark over several years.
• Check beta to see whether the swings suit you.
• Look at alpha to see if returns came from skill or just risk.
• Consider costs, consistency and the fund manager record.

Our page on how to review your portfolio puts this into a yearly routine.

• Beta: how much a fund swings compared with its benchmark.
• Alpha: extra return compared with what the risk would suggest.
• Both look backwards and change with the period.
• Compare within the same category only.

We are distributors rather than investment advisers and we recommend no schemes. If you want help reading these numbers, get in touch.