If you're interested in Nanjing Sample Technology Company Limited (HKG:1708), 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. First, we have company specific volatility, which is the price gyrations of an individual stock. Holding at least 8 stocks can reduce this kind of risk across a portfolio. The second sort is caused by the natural volatility of markets, overall. For example, certain macroeconomic events will impact (virtually) all stocks on the market.

Some stocks mimic the volatility of the market quite closely, while others demonstrate muted, exagerrated or uncorrelated 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.

View our latest analysis for Nanjing Sample Technology

What 1708's beta value tells investors

Zooming in on Nanjing Sample Technology, we see it has a five year beta of 1.23. This is above 1, so historically its share price has been influenced by the broader volatility of the stock market. If the past is any guide, we would expect that Nanjing Sample Technology shares will rise quicker than the markets in times of optimism, but fall faster in times of pessimism. 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 Nanjing Sample Technology's revenue and earnings in the image below.

Does 1708's size influence the expected beta?

With a market capitalisation of HK$6.4b, Nanjing Sample Technology is a small cap stock. However, it is big enough to catch the attention of professional investors. It has a relatively high beta, which is not unusual among small-cap stocks. Because it takes less capital to move the share price of a smaller company, actively traded small-cap stocks often have a higher beta that a similar large-cap stock.