Market capitalisation: large, mid and small cap

The lesson in plain words

The same lesson as the slides above, written out in full.

1. What market cap really tells you

Welcome, and thanks for making time to learn. Market capitalisation sounds technical, but it is really just one small sum that tells you how much the whole company is worth. Once you can read it, you can size up any business at a glance, and that is a skill worth having early.

• Market capitalisation is the total value the market puts on a whole company.
• It is found by multiplying the share price by the number of shares outstanding.
• It answers a plain question: how big is this business, really?
• It is a much better size guide than looking at the share price by itself.
• Investors use it to sort companies into large, mid and small groups.

A quick note: This is financial education only, not financial advice. The numbers used here are illustrative and are meant to explain the idea, not to point you toward any company or decision. Always do your own research and consider speaking to a qualified professional before investing.

2. The formula, with a worked example

Here is the whole idea in one line. You take today's share price and multiply it by how many shares exist, and that gives you the value of the entire company. Notice that if the price drifts up or down through the day, the market cap drifts with it, because the share count usually stays the same.

• Take the share price and multiply it by every share the company has issued.
• In the example, $50 times 10 million shares gives a $500 million market cap.
• The result is the price tag on the entire business, not one slice of it.
• Shares outstanding is the full count of shares held by all owners.
• Because price moves daily, market cap moves with it during trading hours.
• These figures are illustrative and only meant to show the method.

3. Large, mid and small cap

Investors like to sort companies into three buckets by their market cap. Small caps are the little ones, often with more room to grow but also more risk and sharper price moves. Large caps are the giants, usually steadier and more established, though they tend to grow more slowly from such a big base.

• Small-cap companies are the smallest by value and often the youngest.
• Mid-cap companies sit in the middle, still growing but more settled.
• Large-cap companies are the biggest and usually the most established.
• Smaller size can mean more room to grow, but also bigger price swings.
• Larger size tends to mean steadier footing and lower expected growth.
• The dollar cut-offs are rough guides, not fixed rules.

4. A high price is not a big company

This is the trap that catches a lot of people. It feels natural to assume a $500 share means a bigger company than a $20 share, but that is not how it works. A company can split its value into a few expensive shares or many cheap ones, so you always have to multiply price by the share count before you decide how big it really is.

• A high share price on its own tells you almost nothing about company size.
• Company A costs $500 a share but has only 1 million shares, so it is a small company.
• Company B costs $20 a share but has 500 million shares, so it is a large company.
• What matters is price multiplied by share count, not the price alone.
• This is why two shares at very different prices can hide the opposite sizes.
• Always finish the sum before you judge how big a business is.