Lesson 112 min

Why Financial Ratios Matter

Discover the power of financial ratios for stock analysis and learn how professional analysts use them to make investment decisions.

Learning Objectives

  • Understand why ratios are more useful than absolute numbers
  • Learn how professional analysts use financial ratios
  • Recognize the benefits of ratio-based stock analysis
  • Develop the ratio analysis mindset

Why Financial Ratios Matter#

Imagine you're comparing two companies. Company A earned $10 billion last year, while Company B earned $500 million. Which is the better investment? Without additional context, it's impossible to say. Company A might have required $200 billion in assets to generate those earnings, while Company B achieved its results with just $2 billion. This is exactly why financial ratios matter.

A financial ratio is a numerical comparison of two or more financial statement items that reveals insights about a company's performance, valuation, or financial health that raw numbers alone cannot show.

The Power of Standardization#

Financial ratios transform raw financial data into standardized metrics that allow meaningful comparisons. When you calculate Company A's Return on Assets (5%) versus Company B's (25%), the picture becomes clear: Company B is using its resources far more efficiently.

This standardization enables three critical types of analysis:

Comparison TypeWhat It RevealsExample
Cross-companyHow a company stacks up against competitorsApple's P/E vs. Microsoft's P/E
Cross-timeHow a company's performance has evolvedWalmart's margins in 2020 vs. 2024
Cross-industryHow different sectors typically performTech margins vs. Retail margins

How Professional Analysts Use Ratios#

Wall Street analysts don't just look at earnings—they dissect companies using dozens of ratios. Here's how professionals approach ratio analysis:

Screening for Opportunities#

Analysts use ratio-based screens to filter thousands of stocks down to manageable lists. For example, a value investor might screen for:

  • P/E ratio below 15
  • Debt-to-Equity below 0.5
  • Return on Equity above 15%

This quickly eliminates 90% of stocks, letting analysts focus their research time on the most promising candidates.

Due Diligence and Verification#

Once a stock passes initial screening, analysts dive deeper using ratios to verify the investment thesis. They examine:

  • Profitability trends: Are margins improving or declining?
  • Balance sheet health: Can the company service its debt?
  • Operational efficiency: Is management using resources wisely?

The Professional Edge

Professional analysts often calculate 20-30 ratios for each company they analyze in depth. The goal isn't to memorize every ratio, but to understand which ratios matter most for each situation.

Ongoing Monitoring#

Even after investing, analysts continuously monitor key ratios. A sudden change in a ratio can signal:

  • Emerging problems (declining margins, rising debt)
  • Improving fundamentals (better efficiency, strengthening balance sheet)
  • Changes in competitive position

The Ratio Analysis Mindset#

Successful ratio analysis requires more than calculation skills. It demands a specific analytical mindset:

1. Context Is Everything#

A P/E ratio of 25 might be cheap for a high-growth tech company but expensive for a slow-growing utility. Always consider:

  • Industry norms
  • Growth expectations
  • Economic conditions
  • Company lifecycle stage

A single ratio at one point in time tells a limited story. Looking at how ratios change over 3-5 years reveals:

  • Management's execution ability
  • Competitive dynamics
  • Sustainability of performance

3. Multiple Ratios Together#

No single ratio tells the complete story. A company might have an attractive P/E but dangerous debt levels. Or strong profitability but declining efficiency. Always use a combination of ratios from different categories.

Avoid Single-Ratio Decisions

Never make an investment decision based on a single ratio. Enron looked great on many metrics before its collapse. A comprehensive analysis requires multiple ratios across valuation, profitability, and financial health.

4. Understand the "Why"#

When a ratio looks unusual—either too good or too bad—dig deeper. Ask:

  • What's driving this number?
  • Is it sustainable?
  • Is the company manipulating the metric?

The Bottom Line#

Financial ratios are the universal language of stock analysis. They allow you to:

  • Compare any company to any other, regardless of size
  • Track performance over time with consistency
  • Identify both opportunities and risks quickly
  • Make informed decisions based on objective metrics

In the following lessons, we'll explore the five major categories of financial ratios and how to apply them to real investment decisions.

Key Takeaways

  • Financial ratios standardize data to enable meaningful comparisons across companies and time
  • Professional analysts use ratios for screening, due diligence, and ongoing monitoring
  • Context matters: always consider industry, growth stage, and economic conditions
  • Never rely on a single ratio—use multiple ratios from different categories
  • The goal is understanding company fundamentals, not just calculating numbers