Financial Analysis · Lesson 3
Reading the
Income Statement
Big Idea
The income statement (also called the profit and loss statement, or P&L) shows performance over a period — a quarter, a half-year, a year. It answers: did this business make money, and how?
For an investor it is the statement of earning power: revenue growth, pricing, cost control, and how much of each unit of sales survives to the bottom line.
Important caution, worth repeating all course long: profit does not automatically mean cash is available.
The Shape of the Statement
| Line | What it tells you |
|---|---|
| Revenue | Volume and pricing power — the top of the funnel |
| Cost of sales | The direct cost of delivering what was sold |
| Gross profit | What’s left after direct costs — does pricing cover the product? |
| Operating expenses | The cost structure: salaries, rent, marketing, admin |
| Net income | The bottom line — profit or loss after everything, including interest and tax |
Two margins fall straight out of this shape, and you will use them constantly: gross margin (gross profit ÷ revenue) and net margin (net income ÷ revenue). Margins let you compare a small company to a giant, and this year to last year, on equal footing.
The Investor’s Lens
The question is never just “did profit go up?” It is: are sales and margins improving for reasons that make sense?
- Revenue up, gross margin up — pricing power or scale. The good story; verify it.
- Revenue up, gross margin down — growth bought with discounts, or costs rising faster than prices.
- Revenue flat, net income up — cost cutting. Fine once; not a growth engine.
- Profit up on a one-off — asset sales, legal settlements, revaluations. Strip these out before judging the trend.
That last point has a name — quality of earnings. A dollar of profit from selling the product is worth more to you than a dollar from selling the building, because only one of them repeats next year.
A Quick Worked Example
Two companies each report net income of $100,000 on revenue of $1,000,000 — a 10% net margin. Same bottom line, very different stories:
| Item | Company A | Company B |
|---|---|---|
| Revenue | $1,000,000 | $1,000,000 |
| Operating profit | $100,000 | $10,000 |
| Gain on sale of property | — | $90,000 |
| Net income | $100,000 | $100,000 |
Company A earned its profit from operations it can repeat. Company B earned 90% of its profit by selling a building it can only sell once. Identical bottom lines — one durable, one not.
Interactive Checks
Check 1 of 3
A company reports revenue of $2,000,000, cost of sales of $1,200,000, and net income of $150,000.
What are the gross margin and net margin?
Check 2 of 3
Revenue grew 25% this year, but gross margin fell from 40% to 31%.
What is the most likely investor reading of this pattern?
Check 3 of 3
A company's net income doubled, but most of the increase came from a one-time legal settlement received.
How should an investor treat this profit growth?
Common Beginner Mistakes
- ❌ Reading only the bottom line. The path from revenue to net income tells you whether the profit is durable.
- ❌ Confusing profit with cash. Revenue is booked when earned, not when collected — a profitable company can still miss payroll.
- ❌ Comparing dollar profits across companies of different size. Use margins for like-for-like comparison.
- ❌ Extrapolating one-off gains. If it can only happen once, it is not earning power.
Key Takeaways
- The income statement shows performance over a period
- Follow the path: revenue → gross profit → operating expenses → net income
- Gross and net margins make companies and years comparable
- Ask why margins moved, not just whether they did
- One-off gains are not earning power — and profit is not cash
Next Lesson
Reading the Balance Sheet — the financial snapshot: what the company owns and owes, and the strain signals hiding in working capital.