📚 Stock Market Glossary

Clear, beginner-friendly explanations, real-world analogies, and visual formulas for key stock market terminology.

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PEG Ratio (Price/Earnings-to-Growth)

Valuation
💡 Key Takeaway: A stock's price-to-earnings (P/E) ratio divided by the growth rate of its earnings for a specified time period.
Runner Analogy: Athlete A costs $10 with a 5% speed gain. Athlete B costs $30 but speeds up 60% every year. Measuring price per growth unit (PEG 0.5) proves Athlete B is the superior bargain!
😎 10-Second Show-off Pro Tip for Friends!
😎 Show-off Tip: Say, 'Peter Lynch loved using PEG! A tech stock with a PER of 40 isn't expensive if its earnings grow 50% a year, bringing its PEG to 0.8.'

📖 Beginner-Friendly Explanation

STEP 1

Core Concept & Meaning

PEG modifies the traditional P/E ratio by factoring in a company's expected earnings growth rate.

STEP 2

Why It Matters & Mechanism

PEG = PER ÷ Annual EPS Growth Rate.

STEP 3

Practical Investment Tips & Pitfalls

Pioneered by legendary investor Peter Lynch:

  • PEG = 1.0: Stock is fairly valued relative to growth.
  • PEG < 1.0 (e.g. 0.5): Stock is fundamentally undervalued relative to its high growth rate—a prime buying target!
  • PEG > 2.0: Stock is overpriced relative to earnings momentum.
📊 PEG Calculation and Peter Lynch Evaluation Criteria
PEG = PER (30x) ÷ Expected annual profit growth (50%) = 0.6x
▶ PEG < 1.0x: Stock price strongly undervalued relative to growth potential (Peter Lynch purchase strongly recommended!) ▶ PEG > 2.0x: Warning of stock price bubble overvalued relative to growth

⚖️ Key Comparison at a Glance

CategoryCompany A (traditional manufacturing)B Company (AI Big Tech)
Current stock price PER10x (looks cheap)30x (seems expensive)
Annual Profit Growth Rate5% (slow growth)50% (Storm growth)
PEG Index (PER÷Growth Rate)2.0 times (overvalued compared to growth!)0.6 times (tremendously undervalued compared to growth!)
Peter Lynch Diagnosis ResultsNot recommended for purchase as only PER is low and there is no growthStrong buy considering growth potential with PEG below 1.0

📌 Practical Market & Real-World Example

Trading at a 35x PER, the chipmaker's 50% EPS growth delivered a PEG of 0.7, attracting heavy institutional buying.