Market capitalization (also known as market cap) is the total market value of a company. It is one of the most widely used measures to compare the size of a company with other companies.
How do you calculate market capitalization?
The calculation is simple:
Market capitalization = share price x total number of outstanding shares
A company with a share price of 100 euros and 10 million outstanding shares has a market capitalization of 1 billion euros.
Note: market capitalization says nothing about the actual value of a company. It is what the market is willing to pay at this moment. That price can be higher or lower than the intrinsic value.
Categories based on market cap
Large cap (more than 10 billion euros)
Large, established companies with a proven track record. Think of ASML, Shell, Unilever, or in the US, Apple, Microsoft, and Amazon. These companies are relatively stable, often pay dividends, and are less volatile. They form the backbone of most index ETFs.
Mid cap (2 to 10 billion euros)
Medium-sized companies that are often in a growth phase. They combine some stability with growth potential. More volatile than large caps but less risky than small caps.
Small cap (300 million to 2 billion euros)
Smaller companies with higher growth potential but also higher risk. They react more strongly to news and market conditions. The price can rise or fall significantly in a short time. Less liquid than large caps, which can cause additional volatility.
Micro cap (less than 300 million euros)
Very small companies. High risk, low liquidity, but with the possibility of large returns if the company grows. Not suitable as the foundation of your portfolio, but can play a small role for experienced investors.
Market capitalization in crypto
In the crypto market, market cap works the same way: price per coin multiplied by the number of coins in circulation (circulating supply). Bitcoin has by far the highest market capitalization, followed by Ethereum.
With crypto, it is important to look at circulating supply versus total supply. A crypto with a low price but an enormous total supply can have a higher market cap than you would expect. Conversely, a crypto with a high price per coin can have a relatively low market cap if few coins exist.
Why market capitalization matters
Market capitalization helps you assess risk and return expectations:
- Large caps offer more stability but grow more slowly
- Small caps can grow faster but carry more risk
- A balanced portfolio often contains a mix of both
It also helps when comparing companies within the same sector. A technology company with a market cap of 500 million is in a very different phase than one with a market cap of 500 billion. They have different risk profiles, growth expectations, and valuation metrics.
Common misconceptions
- A low share price does not mean a company is cheap. A share at 5 euros can be more expensive than a share at 500 euros. What matters is the market capitalization and the valuation relative to earnings, not the price per share.
- A high market cap is no guarantee of safety. Large companies can also decline significantly. Think of the tech crash of 2000 or the financial crisis of 2008.
- Market cap changes constantly. It is not a fixed number but moves with the price. After a 20% decline, the market cap is also 20% lower.
Market capitalization is a starting point, not a final verdict. It tells you which weight class a company falls into. The rest of the analysis, both fundamental and technical, determines whether it is a good investment.