Company size is just one aspect to consider when evaluating a stock; however, it is important because large and small companies react differently in the market. See Tools of Fundamental Analysis
Lets define size before going any further. There are two ways you can classify a company by size: revenue and market capitalization.
Defining Size
Most people dont use revenue because differences in industries distort how large or small a company is based solely on revenue.Market capitalization or market cap is the standard measure of company size. You compute market cap by multiplying the number of outstanding shares by the current stock price.
For example, if a company had one hundred million shares of common stock outstanding and a current stock price of $55 per share, its market cap would be $5.5 billion (100,000,000 x $55 = $5.5 billion).
This calculation lets you do an apples to apples comparison with any two or more companies.
Finding Market Cap
You can find the market cap of any stock reported on most quotes you find on the Internet such as Yahoo! Finance. Simply enter a symbol and the market cap is among the data reported.Investors categorize companies by market cap and place them under one of these labels although there is not universal agreement on the exact cutoffs.
- Micro Cap - $300 million and under
- Small Cap - $1 billion and under
- Mid Cap - $8 - $1 billion
- Large Cap $100 - $8 billion
- Mega Cap Over $100 billion
Ive come to like these five because of the two high and low extremes. Investing at these two levels is so different that it warrants separate categories.
In the Mega Cap category, you have the Microsofts and Wal Marts and in the Micro Cap category, you have the (name one).
Expect Volatility
If you invest in the micro and small cap markets expect volatility and failure. These numbers ($300 million $1 billion market caps) may sound impressive, but they are most like gnats on elephants butts. Many have life spans about that long. See Understanding Risk.At the same time, Microsoft and Wal Mart were once both small companies that could easily have gone under. While there is great risk in the micro and small cap market, there can be great reward.

