The Calculation
EPS is calculated as: (Net Income − Preferred Dividends) ÷ Average Outstanding Shares. If a company earns £10 million in net income and has 5 million shares outstanding, its EPS is £2.00. This means each share 'earned' £2 of profit during that period.
There are two versions: basic EPS (using current shares outstanding) and diluted EPS (accounting for stock options, convertible bonds, and other instruments that could create new shares). Diluted EPS is the more conservative and widely cited figure.
Why EPS Matters
EPS is the foundation of stock valuation. The price-to-earnings (P/E) ratio — one of the most commonly used valuation metrics — is simply the share price divided by EPS. A stock trading at £30 with EPS of £2 has a P/E of 15. Whether that's cheap or expensive depends on the company's growth rate, industry, and market conditions.
More importantly for traders: quarterly EPS relative to analyst expectations is one of the primary drivers of post-earnings stock price movements. Beat expectations and the stock often rises. Miss them and it often falls.
EPS Growth
A single EPS figure is less useful than the trend. Is EPS growing quarter over quarter? Year over year? Accelerating or decelerating? Companies with consistently growing EPS tend to see rising share prices over time. A sudden decline in EPS growth — even if the company is still profitable — can trigger sharp selloffs.
Limitations
EPS can be manipulated through share buybacks (reducing the number of shares outstanding, which increases EPS even if total profit is flat), accounting adjustments, and one-time charges or gains. Always look at EPS alongside revenue growth, cash flow, and the overall financial picture rather than in isolation.
Key Takeaways
- EPS = net income per outstanding share — the core profitability metric
- Diluted EPS is more conservative and widely used than basic EPS
- EPS relative to analyst expectations drives post-earnings stock moves
- EPS growth trend matters more than any single quarter's figure
- Can be inflated by share buybacks — always look at the broader picture
