What the index measures
The index scores market sentiment from 0 (extreme fear) to 100 (extreme greed). It blends several inputs — volatility, market momentum and volume, social sentiment, Bitcoin dominance and search trends — into one normalised number.
It is a sentiment gauge, not a price prediction. A high score means the crowd is greedy right now; it does not say what price will do next. Think of it as a thermometer for emotion, not a crystal ball.
How to read the extremes
The number is least useful in the middle and most useful at the edges. Extreme fear has historically clustered around capitulation lows, when sellers are exhausted; extreme greed has often preceded pullbacks, when latecomers pile in.
That is the kernel of the classic contrarian read — 'be fearful when others are greedy'. But extremes can persist for weeks in a strong trend, so the index is context, never a standalone trigger.
Using sentiment without getting played by it
Never trade the number alone. Pair it with your own plan: a level you care about, a risk amount you've defined, and a setup you actually take.
Sentiment shifts fast in crypto. The value of the index is that it forces a pause — 'is the crowd euphoric or terrified right now?' — before you act on your own emotion. Log how you felt versus the score in your journal and patterns emerge quickly.