Fear & Greed Index
The Fear & Greed Index is a thermometer for mood, not price. Roughly: 0–25 is extreme fear, 25–45 fear, 45–55 neutral, 55–75 greed, 75–100 extreme greed. A reading of 15, for example, means the market has sold off hard and everyone is huddled up scared.
The ingredients vary by publisher, but the widely used crypto index mixes roughly these: how violently price has swung (volatility), how active and one-sided trading has been, how hot crypto chatter is on social media, Bitcoin dominance, and search volume. Each one alone is noisy, so several are blended into a single number.
Most people read the index contrarian: 'buy when others are fearful, sell when others are greedy' — the old adage, executed by the numbers. Extreme fear means the bottom might be near; extreme greed means the top might be near. That's the hope.
But be careful. The index hitting 10 is a summary of the past — a big crash already happened — not an announcement that the decline is over. In major bear markets the index has parked in extreme fear for weeks while price kept falling. Extreme greed is the same: strong bull markets can hold high readings for a long time while price keeps rising.
Fundamentally, every ingredient is data through yesterday. Volatility, volume, social mentions — all things that already happened. So the Fear & Greed Index works as a mirror showing the market's current state, not a telescope for seeing ahead.
What the data actually shows
'Buying extreme fear wins' is itself a claim that needs backtesting — not an established fact. When Barobara counted Bitcoin chart signals with exactly this method, most were close to a coin flip afterward (setup catalog). There's no reason a sentiment gauge would be the exception. The honest use of the Fear & Greed Index is as a thermometer for which way the mood leans — not something wired to your buy and sell buttons.Common misconceptions
'Extreme fear is a bottom signal' — extreme fear is a summary that says 'a lot of selling already happened,' not 'the selling is done.' In long bear markets there are real stretches where the index sat in extreme fear for weeks while price kept sliding.
'The index predicts the future' — every ingredient is past data (volatility, volume, mentions through yesterday), so it's inherently a backward-looking gauge. It can tell you sentiment is at an extreme; it can't tell you when the extreme resolves.
FAQ
Q. Who makes the Fear & Greed Index?
Multiple publishers make their own. In crypto, the alternative.me index is the famous one; in equities, CNN's Fear & Greed Index is the original. Ingredients and weights differ, so readings can disagree on the same day — better to follow the trend within one index than to compare absolute values.
Q. Has the index ever gone near 0 or 100?
Yes — single digits and readings in the 90s do print during major crashes and manias. The rarity itself is information, but touching an extreme hasn't meant an immediate reversal. Extremes can persist for a long time.