The Key Financial Metrics Every Investor Must Know
A plain-English guide to P/E, EPS, revenue, margins, free cash flow and debt — with healthy benchmarks.
In this lesson you'll learn
Valuation metrics: P/E, forward P/E, PEG ratio
Profitability: gross, operating, and net margin
Per-share metrics: EPS and revenue growth
Balance sheet health: D/E and free cash flow
Healthy benchmarks and red flags for each metric
✓ Good= Typically favourable signal
~ Context= Depends on sector / situation
✗ Caution= Investigate before buying
Valuation Metrics
P/E Ratio
Price ÷ Earnings Per Share
How much investors pay for every $1 of profit. A P/E of 25 means you're paying $25 for $1 of annual earnings.
✓ Good
< 15
Potentially undervalued
~ Context
15–25
Fair value (varies by sector)
✗ Caution
> 40
High expectations baked in
Always compare P/E within the same sector. Tech companies routinely trade at 30–50× while banks trade at 10–15×.
Forward P/E
Price ÷ Next 12-Month Estimated EPS
Uses analyst forecasts instead of past earnings. More forward-looking — but depends on estimates being accurate.
✓ Good
Forward < Trailing
Earnings expected to grow
✗ Caution
Forward > Trailing
Earnings expected to decline
When analysts miss estimates badly, the forward P/E can reset quickly — sometimes causing sharp stock moves.
PEG Ratio
P/E ÷ Earnings Growth Rate
Adjusts P/E for growth. A company with P/E of 30 and 30% earnings growth has PEG of 1.0 — often considered fairly valued.
✓ Good
< 1
Potentially undervalued for growth
~ Context
1–2
Fair valuation
✗ Caution
> 2
Expensive relative to growth
PEG is imperfect — growth rates are estimates. But it's far better than P/E alone for high-growth companies.
Profitability Metrics
Gross Margin
(Revenue − Cost of Goods Sold) ÷ Revenue
What % of sales remains after direct production costs. High gross margin = pricing power or scalable business model.
✓ Good
Software: 60–80%+
Exceptional
~ Context
Retail: 20–40%
Normal for sector
✗ Caution
Falling margin
Cost pressure or competition
More important than the absolute number is the trend. Margins expanding = improving business quality. Margins shrinking = red flag.
Operating Margin
Operating Income ÷ Revenue
Profitability after all operating expenses (including R&D, SG&A). The best single profitability metric for comparing companies.
✓ Good
> 20%
Excellent — business has strong moat
~ Context
10–20%
Good
✗ Caution
< 5%
Thin — vulnerable to shocks
A company can have a high gross margin but low operating margin if it spends heavily on R&D/sales. Both matter.
Net Profit Margin
Net Income ÷ Revenue
How much of every dollar of revenue becomes profit after all costs including tax. The 'bottom line' profitability.
✓ Good
> 15%
Strong
~ Context
5–15%
Acceptable
✗ Caution
< 5% or negative
Struggling or pre-profit
Negative net margin doesn't always mean bad — high-growth companies like early Amazon often invested aggressively. Check if losses are by choice or necessity.
Per-Share & Earnings Metrics
EPS (Earnings Per Share)
Net Income ÷ Shares Outstanding
Profit divided among all shareholders. Growing EPS over time is the core driver of long-term stock price appreciation.
✓ Good
YoY EPS growth > 15%
High growth business
~ Context
Stable positive EPS
Mature business
✗ Caution
Declining or negative EPS
Investigate cause
Watch for share buybacks inflating EPS without real profit growth. If net income is flat but shares decrease, EPS rises — not a real improvement.
Revenue Growth
(Current Revenue − Prior Period Revenue) ÷ Prior Period Revenue
How fast the company's top line is expanding. The most important signal for early-stage and growth companies.
✓ Good
> 20% YoY
High growth
~ Context
5–20% YoY
Steady growth
✗ Caution
Declining
Investigate — could be structural
High revenue growth with no path to profitability is not always good (see Peloton, Snap post-IPO). Pair growth with a margin trajectory.
Balance Sheet & Cash Metrics
Debt-to-Equity (D/E)
Total Debt ÷ Total Shareholders' Equity
How much a company relies on borrowing vs. its own capital. High debt amplifies both gains and losses.
✓ Good
< 0.5
Conservative — strong balance sheet
~ Context
0.5–2
Normal for most sectors
✗ Caution
> 3
High leverage — monitor closely
Capital-intensive industries (utilities, airlines, banks) routinely run high D/E. Always compare within sector, not in isolation.
Free Cash Flow (FCF)
Operating Cash Flow − Capital Expenditures
Cash left over after maintaining and growing the business. Often called the truest measure of business quality — harder to manipulate than earnings.
✓ Good
FCF growing YoY
Business generating real value
~ Context
FCF positive but flat
Mature business
✗ Caution
Persistent negative FCF
Burning cash — check runway
A company can report accounting profit but generate no cash (revenue recognition timing, non-cash charges). Always cross-check EPS with FCF.
Quick-reference: the 8 metrics to check on every stock
1
P/E or Forward P/E
Is the valuation reasonable?
2
Revenue Growth (YoY)
Is the business expanding?
3
Gross Margin
Does it have pricing power?
4
Operating Margin
Is it efficiently run?
5
EPS trend
Is profit per share growing?
6
Free Cash Flow
Is the profit real cash?
7
Debt-to-Equity
Is the balance sheet safe?
8
PEG Ratio
Is the growth worth the price?
Quick Knowledge Check
3 questions · test what you've just learned
1
A stock has a P/E of 30. The sector average P/E is 15. What does this most likely mean?
2
Which financial metric is considered the hardest to manipulate and the most reliable signal of real profitability?
3
A company has a PEG ratio of 0.7. How would you interpret this?
✓ Key takeaways from Lesson 4
P/E = Price ÷ EPS. Always compare P/E within the same sector, not across industries.
PEG ratio corrects P/E for growth — a PEG under 1 often signals an undervalued growth stock.
Gross margin and operating margin reveal pricing power and operational efficiency.
Free cash flow is the hardest metric to fake — it's the most reliable profitability signal.
Consistently growing EPS + expanding margins + positive FCF = the core of a quality business.
See all these metrics on real stocks — free
BriMindInvest's stock analysis pages show P/E, margins, FCF, EPS growth, and AI scores for every stock. Put your new knowledge to work on real data.