If you own shares in Simonds Group Limited (ASX:SIO) then it’s worth thinking about how it contributes to the volatility of your portfolio, overall. In finance, Beta is a measure of volatility. Modern finance theory considers volatility to be a measure of risk, and there are two main types of price volatility. The first category is company specific volatility. This can be dealt with by limiting your exposure to any particular stock. The other type, which cannot be diversified away, is the volatility of the entire market. Every stock in the market is exposed to this volatility, which is linked to the fact that stocks prices are correlated in an efficient market.

Some stocks see their prices move in concert with the market. Others tend towards stronger, gentler or unrelated price movements. Beta is a widely used metric to measure a stock’s exposure to market risk (volatility). Before we go on, it’s worth noting that Warren Buffett pointed out in his 2014 letter to shareholders that ‘volatility is far from synonymous with risk.’ Having said that, beta can still be rather useful. The first thing to understand about beta is that the beta of the overall market is 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 Simonds Group

What SIO’s beta value tells investors

Zooming in on Simonds Group, we see it has a five year beta of 0.86. 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). Share price volatility is well worth considering, but most long term investors consider the history of revenue and earnings growth to be more important. Take a look at how Simonds Group fares in that regard, below.

How does SIO’s size impact its beta?

With a market capitalisation of AU$47m, Simonds Group is a very small company by global standards. It is quite likely to be unknown to most investors. It is not unusual for very small companies to have a low beta value, especially if only low volumes of shares are traded. Even when they are traded more actively, the share price is often more susceptible to company specific developments than overall market volatility.