The Short Version
Every valuation ratio from the Stock Market guide is only as reliable as the accounting numbers feeding it. A low P/E built on inflated, low-quality earnings isn't actually a bargain. Strong ROE built on excessive debt isn't the same as strong ROE built on genuine efficiency. The real skill of investment analysis is combining both guides: use accounting principles to judge whether the underlying numbers are trustworthy, then use market/valuation ratios to judge whether the price being asked for those numbers is reasonable.
Explain It Like I'm 10
Imagine judging a used car purely by its sale price without ever popping the hood to check the engine. That's what using stock ratios WITHOUT checking accounting statements is like. A 'cheap-looking' P/E ratio built on shaky, low-quality earnings isn't actually a bargain — it's a car with a great price tag and a cracked engine block hidden underneath. Combining both guides means popping the hood (accounting) before trusting the sticker price (valuation ratios).
Step-by-Step Example
- 1 Stock shows a low P/E of 8, which looks cheap compared to the industry average of 18.
- 2 Check the accounting statements: operating cash flow has been falling for 3 years straight, and accounts receivable is ballooning.
- 3 That combination suggests the 'cheap' P/E might reflect real underlying problems, not a hidden bargain.
- 4 Compare to a second stock with P/E of 22 (seemingly pricier), but strong, growing operating cash flow and a clean balance sheet.
- 5 The second stock's higher P/E may actually be far more justified once the accounting quality behind the numbers is considered — price alone never tells the whole story.
Quick Recap
- ✓ Good analysis reads the financial statements first, and treats stock ratios as a second layer built on top of them.
- ✓ When something looks 'too good' in a ratio (unusually low P/E, unusually high ROE or margin), the accounting statements are exactly where you go to find out why.