If you own shares in Air T, Inc. (NASDAQ:AIRT) 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. 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 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 mimic the volatility of the market quite closely, while others demonstrate muted, exagerrated or uncorrelated price movements. Some investors use beta as a measure of how much a certain stock is impacted by market risk (volatility). While we should keep in mind that Warren Buffett has cautioned that 'Volatility is far from synonymous with risk', beta is still a useful factor to consider. To make good use of it you must first know that the beta of the overall market is one. A stock with a beta greater than one is more sensitive to broader market movements than a stock with a beta of less than one.

See our latest analysis for Air T

What we can learn from AIRT's beta value

Given that it has a beta of 1.29, we can surmise that the Air T share price has been fairly sensitive to market volatility (over the last 5 years). If this beta value holds true in the future, Air T shares are likely to rise more than the market when the market is going up, but fall faster when the market is going down. 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 Air T's revenue and earnings in the image below.

How does AIRT's size impact its beta?

With a market capitalisation of US$32m, Air T is a very small company by global standards. It is quite likely to be unknown to most investors. It has a relatively high beta, suggesting it is fairly actively traded for a company of its size. Because it takes less capital to move the share price of a small company like this, when a stock this size is actively traded it is quite often more sensitive to market volatility than similar large companies.

What this means for you:

Since Air T has a reasonably high beta, it's worth considering why it is so heavily influenced by broader market sentiment. For example, it might be a high growth stock or have a lot of operating leverage in its business model. In order to fully understand whether AIRT is a good investment for you, we also need to consider important company-specific fundamentals such as Air T’s financial health and performance track record. I urge you to continue your research by taking a look at the following: