@BrianFeroldi: Capitalism is brutal.If you ...

@BrianFeroldi
14 views Sep 05, 2025
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Capitalism is brutal.

If you invest, you MUST know how to identify a moat.

Here are 9 financial “rules of thumb” that Warren Buffett uses to tell if a company has one:
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1: Gross Margin

Found: Income Statement

Formula: Gross Profit / Revenue

Moat: Consistently above 40%

No Moat: Under 40% & volatile
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Buffett’s logic:

A consistently high gross margin signals that the company isn’t competing exclusively on price.

A high gross margin also provides ample gross profit to pay expenses and leaves money for shareholders.
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2: Sales, General, and Administrative Expenses

Where: Income Statement

Formula: SG&A / Gross Profit

Moat: Consistently under 30%

No Moat: Over 80% & volatile
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Buffett’s logic:

Wide moat companies don’t need to spend a lot on overhead to operate. No moat businesses do.

Buffett looks for companies that consistently spend under 30% of their gross profit on SG&A.
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3: Depreciation Expense

Where: Income Statement & Cash Flow Statement

Formula: Depreciation / Gross Profit

Moat: Consistently under 10%

No Moat: Volatility & high
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Buffett’s logic:

If depreciation is consistently less than 10% of gross profit, it’s a sign that the company doesn’t need a lot of capital expenditure assets to maintain its competitive advantage and has a moat.
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4: Interest Expense

Where: Income Statement

Formula: Interest Expense / Operating Income

Moat: Consistently under 15%

No Moat: Over 50% & volatile
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Buffett’s logic:

Great businesses have such wonderful economics that they are don’t need to rely on debt

While this number varies greatly from industry to industry, it’s a great sign if a company consistently spends less than 15% of its operating income on interest
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5: Income Tax Expenses

Where: Income Statement

Formula: Income Tax Paid / Pre-tax Income (Earnings Before Tax)

Moat: Consistently pays the full amount (~21% in U.S.)

No Moat: Negative, erratic
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Buffett’s logic:

Wide moat businesses make so much money that they are consistently forced to pay their full share of taxes.

Companies that consistently have negative or an erratic income tax bills aren't as likely to have a durable moat
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6: Profit Margin (Net Margin)

Where: Income Statement

Formula: Net Income / Revenue

Moat: Consistently above 20%

No Moat: Below 10%, negative, and volatile
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Buffett’s logic:

Companies that consistently convert 20% of their revenue into net income likely have a moat.

If this number is under 10%, negative, or volatile, it's an indication that competition is fierce.

(There’s plenty of nuance between 10% and 20%)
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7: Capital Expenditures

Where: Income Statement & Cash Flow Statement

Formula: Capital Expenditures / Net Income

Moat: Consistently under 25%

No Moat: Consistently above 75%
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Buffett’s logic:

Capital expenditures eat into profits. Companies that don’t have to spend big on capex have more money to reward shareholders

Important: Capital Expenditures can vary greatly from year to year. Averaging the result over 10+ years is best
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8: Total Liabilities to Adjusted Shareholder Equity

Where: Balance Sheet

Formula: Total Liabilities / Shareholder Equity

Moat: Below 0.80

No Moat: Over 2.00
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Buffett’s logic:

Wide moat businesses finance themselves with profits, not debt

However, stock buybacks can throw off this equation

Adjust for this by adding back any treasury stock to the shareholder equity number
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9: Return on Shareholders’ Equity

Where: Balance Sheet & Income Statement

Formula: Net Income / Shareholder Equity

Moat: Consistently above 15%

No Moat: Below 10%, negative, or volatile
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Buffett’s logic:

Return on equity shows how effectively management is reinvesting its profits. A number consistently over 15% indicates that the business has a moat

Under 10%, negative, or volatile indicates that the business is struggling with competition.
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3 Important notes:

A) These “rules of thumb” are only useful when a company is fully optimized for profits (phases 4 & 5)
B) CONSISTENCY is key
C) There are PLENTY of exceptions & nuances to these rules
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