◐ Behavioral
◆ The PatternThe two dominant market emotions.
The two primal market emotions — fear and greed — drive the pendulum of market psychology.
Greed cycle: opportunity → interest → excitement → euphoria → "I can't lose"
Fear cycle: concern → worry → anxiety → panic → "I must get out at any price"
Fear cycle: concern → worry → anxiety → panic → "I must get out at any price"
Warren Buffett's famous rule: "Be fearful when others are greedy, and greedy when others are fearful."
The CNN Fear & Greed Index aggregates 7 market signals into a 0–100 scale measuring current dominant emotion.
Pattern bridge: The cycle between fear and greed drives volatility — the emotional driver behind variance. In ML, softmax temperature mimics this: cold = greedy certainty, hot = fearful uniformity.
Performance in practice
- The CNN Fear & Greed Index as a contrarian signal: buying when index < 20 (extreme fear) historically returns +14.5% over the following year vs +9.5% average
- VIX > 30 + Fear Index < 15 has preceded major bottoms in 2009, 2011, 2018, 2020
- Extreme greed (>80) is a weaker sell signal — markets can stay euphoric longer than they stay panicked
When to use this
✓ Use when: Timing lump-sum additions to a portfolio. Gauging whether a sell-off is panic-driven or fundamentally justified. As a contrarian filter — consider buying when others are fearful.
✗ Skip when: Day trading — sentiment indices update too slowly. Ignoring in a disciplined DCA strategy where emotions shouldn't affect contributions. As a standalone timing signal — always combine with price/volume.