If you're interested in Ramky Infrastructure Limited (NSE:RAMKY), then you might want to consider its beta (a measure of share price volatility) in order to understand how the stock could impact your portfolio. Volatility is considered to be a measure of risk in modern finance theory. Investors may think of volatility as falling into two main categories. The first type is company specific volatility. Investors use diversification across uncorrelated stocks to reduce this kind of price volatility across the portfolio. The second type is the broader market volatility, which you cannot diversify away, since it arises from macroeconomic factors which directly affects all the stocks on the market.

Some stocks mimic the volatility of the market quite closely, while others demonstrate muted, exagerrated or uncorrelated price movements. Beta can be a useful tool to understand how much a stock is influenced by market risk (volatility). However, Warren Buffett said 'volatility is far from synonymous with risk' in his 2014 letter to investors. So, while useful, beta is not the only metric to consider. To use beta as an investor, you must first understand that the overall market has a beta of one. A stock with a beta below one is either less volatile than the market, or more volatile but not corellated with the overall market. In comparison a stock with a beta of over one tends to be move in a similar direction to the market in the long term, but with greater changes in price.

See our latest analysis for Ramky Infrastructure

What we can learn from RAMKY's beta value

Zooming in on Ramky Infrastructure, we see it has a five year beta of 0.81. This is below 1, so historically its share price has been rather independent from the market. This means that -- if history is a guide -- buying the stock would reduce the impact of overall market volatility in many portfolios (depending on the beta of the portfolio, of course). Many would argue that beta is useful in position sizing, but fundamental metrics such as revenue and earnings are more important overall. You can see Ramky Infrastructure's revenue and earnings in the image below.

Could RAMKY's size cause it to be more volatile?

With a market capitalisation of ₹3.5b, Ramky Infrastructure is a very small company by global standards. It is quite likely to be unknown to most investors. Very small companies often have a low beta value because their share prices are not well correlated with market volatility. This could be because the price is reacting to company specific events. Alternatively, the shares may not be actively traded.