Bitcoin Fear & Greed Index, explained

By btclyzer · Updated May 14, 2026 · 8 min read

The Bitcoin Fear & Greed Index is a 0–100 score published daily by Alternative.me. It mashes together five public signals — BTC volatility, market momentum, social mentions, BTC dominance and Google Trends — into a single number that summarises how nervous (or euphoric) the crypto market feels. It's useful as context, terrible as a standalone trade trigger.

What is the Fear & Greed Index?

The Fear & Greed Index is a sentiment gauge. Instead of asking "what is the price doing?", it asks "how does the market feel about the price?" The crypto version was launched by Alternative.me in 2018, inspired by CNN's older Fear & Greed Index for US stocks.

The result is a single number between 0 and 100, updated once per day. Zero means the market is paralysed by fear. One hundred means it's drunk on greed. Everything in between is shades of the same thing.

How is the 0–100 score calculated?

Alternative.me combines five public components, each with a fixed weight:

Volatility (25%) — current BTC volatility and max drawdown compared with the 30-day and 90-day averages. Unusually high volatility is treated as a fear signal.
Market momentum & volume (25%) — current trading volume and momentum relative to recent averages. High volume combined with a strong uptrend reads as greed.
Social media (15%) — public mentions and engagement on X (Twitter), measured against typical baseline activity. Spikes in chatter usually mean greed.
Bitcoin dominance (10%) — BTC's share of total crypto market capitalisation. Rising dominance signals a flight to "safer" Bitcoin (fear in altcoins); falling dominance often coincides with risk-on euphoria across alts.
Google Trends (10%) — search interest for Bitcoin-related queries, weighted heavily toward fear-related terms (e.g. "bitcoin price manipulation", "bitcoin crash").

A sixth component — investor surveys — was part of the original index but Alternative.me discontinued it in 2021 due to data-quality concerns. The remaining five components are renormalised to add up to 100%.

How to read the value

Extreme Fear

Fear

Greed

Extreme Greed

0255075100

Alternative.me's official bands. The "Neutral" zone is a single point at exactly 50 — anything below tilts toward fear, anything above toward greed.

Most readers default to the contrarian mantra: "Be fearful when others are greedy, greedy when others are fearful." That heuristic is famously associated with Warren Buffett and has some basis in market history, but as a mechanical trading rule on the daily F&G score it's at best mediocre and at worst dangerous.

Historical extremes — what actually happened

A few data points to ground the index in real moves rather than vibes:

March 2020 (COVID crash) — index touched 8. BTC was around $5,000. Anyone who bought at "extreme fear" and held was richly rewarded over the following 18 months.
June 2022 (Luna / 3AC collapse) — index hit 6. BTC near $17,000. Again, a multi-year buying opportunity in hindsight.
November 2021 (cycle top) — index reached 84. BTC at $69,000. The classic "extreme greed equals top" narrative looked right — for about three months. The drawdown into mid-2022 was brutal.
Early 2024 spot ETF approval rally — the index stayed pinned in the 70s and low 80s for weeks. Selling every "extreme greed" reading would have meant missing most of the move from $40k to $73k.

Two patterns emerge. Extreme fear (below ~15) has marked durable bottoms more reliably than extreme greed has marked tops. And both extremes can persist for weeks — using the index as a same-day reversal trigger is almost always premature.

Limitations and common misuses

The Fear & Greed Index has real weaknesses you should keep in mind:

It is a snapshot, not a forecast. Knowing today's score tells you about today's sentiment, not tomorrow's price.
Sentiment can stay extreme for months. The market can stay irrational longer than a contrarian can stay solvent.
It is Bitcoin-centric. Most components measure BTC, not altcoins. Treating it as a "crypto sentiment" proxy for memecoins is approximate at best.
It is uncorrelated with fundamentals. A halving cycle, an ETF approval, a regulatory shock — none of those events are inputs to the index. They affect price, the index reacts after the fact.
The contrarian rule has tail risk. Buying every "extreme fear" reading sounds simple until you size positions during a real bear market and watch them keep falling.

How btclyzer uses the Fear & Greed Index

btclyzer treats sentiment as one input among many. The Fear & Greed value is fetched live from Alternative.me and contributes to the adaptive multi-factor algorithm that produces the BUY / SELL / HODL rating. Its weight is timeframe-dependent: on the 1H and 4H charts sentiment moves too slowly to matter much, so the algorithm leans harder on RSI, MACD and volume. On 1D, 1W and 1M, sentiment carries more weight because it tracks the slower cycle dynamics that those timeframes actually care about.

This is why a reading of 20 on the dashboard doesn't automatically flip the rating to BUY. The algorithm asks: are the trend indicators (EMA 50, EMA 200) aligned bullish? Is the MACD histogram turning up? Is volume confirming? If sentiment is screaming "fear" but the technical structure says "still in a downtrend", the rating will stay HOLD or SELL until other inputs catch up.

See the Fear & Greed Index live

btclyzer pulls the latest value and folds it into a single BUY / SELL / HODL rating across five timeframes — alongside RSI, MACD, EMA, on-chain data and CBBI.

Launch the dashboard →

FAQ

Where does the Bitcoin Fear & Greed Index data come from?

The most widely cited Bitcoin Fear & Greed Index is published by Alternative.me. It aggregates five public data sources: BTC price volatility, market momentum and trading volume, social media mentions, Bitcoin's share of total crypto market capitalisation, and Google Trends search interest for Bitcoin-related queries.

How often does the Fear & Greed Index update?

Alternative.me updates the index once a day. Each daily value reflects the average sentiment across the previous 24 hours of data. btclyzer fetches the latest value live and recomputes its rating every minute server-side.

Should I buy when fear is extreme and sell when greed is extreme?

That contrarian rule is popular but oversimplified. Extreme fear can persist for weeks during a real bear market and extreme greed can last for months in a confirmed bull run. The Fear & Greed Index is most useful when combined with technical indicators, on-chain data and macro context — not as a standalone trade trigger.

Is there a separate Fear & Greed Index for stocks?

Yes — CNN Business publishes a Fear & Greed Index for the US stock market using different inputs (S&P 500 momentum, put/call ratio, junk bond demand, market breadth, safe-haven demand). The crypto version published by Alternative.me is a separate metric designed specifically around Bitcoin and digital assets.

Does the index work for altcoins?

Alternative.me's index is Bitcoin-centric — most of its components measure BTC volatility, BTC momentum, BTC dominance and Bitcoin-related social mentions. Altcoin markets are correlated with Bitcoin but not identical; treating the BTC Fear & Greed Index as an altcoin sentiment gauge is approximate at best.