skills/bigdata-investment-memo/references/graham-dodd-principles.md

# Graham & Dodd Principles

Core investment principles from Security Analysis that anchor all equity research.

## Intrinsic Value

**Definition**: The value justified by the facts - assets, earnings, dividends, and definite prospects - as distinguished from distortions caused by psychology or manipulation.

**Key Insight**: Intrinsic value exists independent of market price. The analyst's job is to estimate it, then compare to what the market offers.

### Intrinsic Value Framework

| Component | What to Assess |
|-----------|----------------|
| **Asset Value** | Tangible book value, liquidation value, replacement cost |
| **Earnings Power** | Normalized earnings capacity under current conditions |
| **Growth Value** | Present value of expected earnings above current level |
| **Franchise Value** | Premium from sustainable competitive advantage |

**Practical Application**:
1. Estimate each component independently
2. Weight based on reliability (asset value most reliable, growth least)
3. Compare sum to market price
4. Require discount before investing

## Margin of Safety

**Definition**: The difference between intrinsic value and market price, providing a cushion against analytical error and unforeseen adversity.

**Core Principle**: "The function of the margin of safety is, in essence, that of rendering unnecessary an accurate estimate of the future."

### Margin of Safety Requirements

| Investment Quality | Minimum Margin |
|-------------------|----------------|
| High quality, stable | 20-30% |
| Average quality | 30-40% |
| Speculative, uncertain | 40-50%+ |
| Distressed situations | 50%+ |

**Why Margin Matters**:
- Valuation is inherently imprecise
- Unforeseen events occur regularly
- Forecasts systematically err toward optimism
- Margin compensates for the unknowable

### Sources of Margin

1. **Valuation discount**: Price below conservatively estimated intrinsic value
2. **Asset coverage**: Tangible assets exceed liabilities by meaningful amount
3. **Earnings stability**: Consistent earnings through economic cycles
4. **Conservative assumptions**: Using below-average multiples, above-average discount rates

## Investment vs. Speculation

**Graham's Definition**: "An investment operation is one which, upon thorough analysis, promises safety of principal and an adequate return. Operations not meeting these requirements are speculative."

### The Three Tests

| Test | Investment | Speculation |
|------|------------|-------------|
| **Thorough analysis** | Deep fundamental research | Superficial or momentum-based |
| **Safety of principal** | Downside protected by value | Relies on price appreciation |
| **Adequate return** | Reasonable given risk | Requires exceptional outcome |

### Speculation Warning Signs

- Paying for distant growth with no current earnings support
- Relying on greater fool theory (someone will pay more)
- Ignoring valuation because "it's different this time"
- Buying primarily on price momentum
- Cannot articulate intrinsic value

## Quality Anchoring

**Principle**: Begin with quality assessment before considering price. Poor quality at a low price may still be a poor investment.

### Quality Hierarchy

| Tier | Characteristics | Investment Approach |
|------|-----------------|---------------------|
| **High Quality** | Strong franchise, consistent earnings, fortress balance sheet | Accept lower margin of safety |
| **Average Quality** | Decent business, cyclical earnings, adequate capital | Require meaningful discount |
| **Low Quality** | Weak competitive position, volatile earnings, leverage concerns | Require very large discount or avoid |
| **Speculative** | Unproven business, no earnings, high uncertainty | Generally avoid |

### Quality Indicators

**Positive**:
- Consistent earnings over 10+ years
- Strong debt coverage ratios
- Consistent dividend history
- Leading market position
- High returns on capital

**Negative**:
- Earnings volatility or losses
- High or rising debt levels
- Dividend cuts or omissions
- Declining market share
- Returns below cost of capital

## Applying Graham-Dodd Today

The principles remain timeless even as markets evolve:

1. **Always estimate intrinsic value** before considering whether to buy
2. **Require margin of safety** appropriate to the uncertainty
3. **Distinguish investment from speculation** - be honest about which you're doing
4. **Quality first, price second** - don't let cheapness justify poor businesses
5. **Trust cash over accruals** - earnings are opinion, cash is fact
6. **Be skeptical of forecasts** - including your own

**The Ultimate Test**: Would you be comfortable owning this business if the market closed for five years? If not, you're speculating, not investing.