Prompt d'Analyse d'Investissement de William Gann

❌ **Misconception 1**: "Gann made $50 million from trading"
- **Reality**: This figure has never been verified. According to his son John Gann, Gann's estate was approximately **$100,000** at death. Most of his income came from **selling books and courses**, not trading profits.

❌ **Misconception 2**: "Gann Theory can precisely predict markets"
- **Reality**: Many of Gann's "successful predictions" were promoted by himself or followers after the fact. The famous 92.3% win rate test has serious credibility questions among modern analysts.

❌ **Misconception 3**: "Learning Gann Theory guarantees consistent profits"
- **Reality**: No prominent hedge fund or institutional investor worldwide uses Gann Theory as their core strategy. If the theory worked, it should produce verifiable, consistent return records.

❌ **Misconception 4**: "Gann's mystical elements (astrology, etc.) are pseudoscience"
- **Reality**: More accurately, Gann attempted to apply **natural cyclical patterns** to markets. While astrology isn't recognized by modern science, his emphasis on **time cycles** has some validity — economies and markets do exhibit cyclical fluctuations.

⚠️ **Extremely difficult to truly master; not recommended for ordinary investors**:

**Challenges**:
- ❌ **Extremely complex**: Gann Theory involves astronomy, astrology, biblical numerology, and other esoteric elements; the system is vast with no unified standards
- ❌ **Highly subjective**: Different analysts may draw completely different Gann angles on the same chart, reaching opposite conclusions
- ❌ **Hindsight bias**: Many "successful cases" of Gann Theory are retrospective analyses; real-time application effectiveness is questionable
- ❌ **Lacks statistical validation**: Modern academic research has not confirmed Gann Theory has stable predictive power

**Useful principles to borrow**:
- ✅ **Strict stop-losses**: Gann emphasized limiting losses to no more than 10% of capital per trade — an excellent risk management principle
- ✅ **Time awareness**: Pay attention to market cyclical characteristics (e.g., recessions roughly every 10 years)
- ✅ **Disciplined trading**: Gann developed 28 trading rules emphasizing execution discipline

**Honest advice**: Rather than spending years studying Gann Theory's complex system, invest that time learning fundamental business analysis and asset allocation. Investment returns come from value created by businesses, not angle lines on charts.

**Core Comparison**:

| Dimension | Gann | Buffett |
|-----------|------|--------|
| **Analytical basis** | Mathematics/geometry/time cycles | Business fundamentals/financial statements |
| **Core tools** | Angle lines, Square of Nine, time cycles | Free cash flow, ROE, moats |
| **Philosophy** | Markets follow precise mathematical laws | Markets reflect business value long-term |
| **Trading frequency** | High frequency (intraday to weekly) | Extremely low (holds for years or lifetime) |
| **Focus** | Price movements and time nodes | Business quality and valuation levels |
| **Risk management** | Strict stop-losses (no more than 10% per trade) | Through margin of safety and diversification |

**Essential difference**: Gann was a **pure market analyst** who believed price charts contain all information; Buffett is a **business analyst** who sees stocks as business ownership. They represent the two extremes of technical vs. fundamental analysis.

**Buffett's view**: Buffett never uses technical analysis and once said, "If past history was all there was to the game, the richest people would be librarians."

W.D. Gann's method is best suited when market conditions align with Technical analysis, time cycles, geometric angles characteristics. Investors should decide whether to adopt this strategy based on their risk tolerance and investment objectives.

Gann Theory is a market analysis system combining **mathematics, geometry, and time cycles**, with the core idea that "**price and time have precise mathematical relationships**."

**Three Core Tools**:
1. **Gann Angles**: Based on the 45-degree angle (1x1 line), representing price-time equilibrium. Price above the 45-degree line indicates bullish trend; below indicates bearish. Common angles include 1x2 (26.5 degrees), 2x1 (63.75 degrees), etc.
2. **Time Cycle Theory**: Gann believed markets repeat in fixed cycles. Key cycles include **7, 10, 20, 30, and 60 years**. He especially emphasized "**time is more important than price**"
3. **Square of Nine**: Numbers arranged in a spiral pattern to calculate key support/resistance levels

**Famous predictions**:
- In 1909, under observation by a Wall Street Journal reporter, made 286 trades in 10 months with a **92.3% win rate**
- Predicted the 1929 crash in advance

**Core belief**: Markets are not random; history repeats according to precise mathematical laws.

**W.D. Gann** (1878-1955) is one of the most legendary figures in technical analysis history. In his famous 90-day experiment in 1909, he publicly made **286 trades with 264 wins**, achieving a success rate of 92.3%, turning $5,000 into $12,000 and shocking Wall Street.

**Core of Gann Theory**:
1. **Time cycles**: Market movements follow natural laws and mathematical rules, with important turning points appearing at specific time nodes (such as 7, 10, 20-year cycles)
2. **Geometric angles**: The relationship between price and time can be represented by geometric angles, with the most important being the **45-degree line (1×1 line)**, representing balance between price and time. Breaking above or below the 45-degree line signals trend change
3. **Square relationship between price and time**: When price movement equals the square root of time period, markets tend to turn
4. **Support and resistance**: Historical highs/lows and important percentages (50%, 61.8%, etc.) form strong support or resistance

Gann proved that markets are not random but follow patterns. His theories are still widely used by technical analysts globally today.

Controversial, partially effective:

✅ **Effective parts**:
- Time cycle analysis valuable at major turning points
- Support/resistance concepts widely used
- 28 trading rules still practical today

⚠️ **Controversial parts**:
- Precise angle predictions lack statistical validation
- Number mysticism (144, 7) lacks scientific basis
- Survivorship bias: successes publicized, failures ignored

💡 **Advice**: Use Gann tools as auxiliary reference, combined with modern technical and fundamental analysis

The core of Gann Theory is "balance between time and price":

**Three pillars**:
1. **Time cycles**: Markets follow specific time patterns (30, 60, 90-year grand cycles)
2. **Geometric angles**: Price moves along specific angles (1×1 line = 45 degrees, time = price)
3. **Number vibrations**: Specific numbers carry market significance (7, 12, 144)

**Key tools**:
- Gann Angles
- Gann Square
- Time Windows

Gann believed time is the primary factor determining market turning points:

**Core logic**:
- Price changes are the result of time cycles, not the cause
- When time cycles reach key nodes, markets inevitably turn
- Even if fundamentals unchanged, markets turn when time arrives

**Practical significance**:
- Focus on time windows, not just price targets
- When multiple time cycles resonate, turning signals are strongest
- Time can correct price, but price cannot change time