Reading a Company: Market Cap, EPS, P/E

Four numbers tell you more about a company than any headline. None of them tell you whether the stock will go up, and pretending otherwise is where most investing mistakes begin.

Last verified 2026-07-16

The share price on its own tells you nothing

A $12 stock is not cheaper than a $600 stock. Price per share depends entirely on how many slices the company was cut into, and a company can change that overnight with a split without anything real happening.

Market capitalisation is the number that means something: share price times shares outstanding, which is what the market says the whole company is worth. A $12 stock with 10 billion shares is a far larger company than a $600 stock with 2 million.

This is the single most common beginner error, and it has a specific shape — buying the low-priced stock because more shares feel like more ownership. They aren't. Owning 1,000 shares of a company cut into a billion pieces is a smaller stake than owning 10 shares of one cut into a thousand.

From profit to what you're paying for it

Earnings per share takes the company's net income and divides it by shares outstanding, converting a company-level number into a per-slice one so it can be compared against the price of a slice.

P/E then divides share price by EPS: dollars paid per dollar of annual earnings. A P/E of 20 means you're paying $20 for each $1 the company currently earns per year.

The word 'currently' is doing enormous work there. The denominator is earnings already reported, while the price in the numerator reflects what buyers expect next. So P/E is never a measure of cheapness — it's a summary of the gap between what a company earns now and what the market thinks it will earn later.

Two traps built into these ratios

The value trap: a low P/E usually means the market expects earnings to fall, not that everyone else missed a bargain. Buying a P/E of 6 on the assumption the number will hold often means buying a business whose earnings are about to shrink, which raises the ratio right back.

The yield trap works the same way through a different formula. Dividend yield is dividend divided by price, so a collapsing price mechanically inflates the yield. A stock showing 12% has usually fallen hard because the market expects the dividend to be cut.

Both traps share one structure worth recognising: a ratio looks attractive because its denominator or numerator moved for a bad reason. Whenever a metric suddenly looks unusually good, check which part of the fraction moved and why — that question defuses most of them.