Altcoin Season Radar

How the Altcoin Season Radar works

Short answer: An altcoin season index measures how many large altcoins beat Bitcoin over a set period. This radar takes the top 50 altcoins by market cap, excluding stablecoins and wrapped or staked tokens, and counts the share whose 30-day price change exceeds Bitcoin's. 75 or more is labeled Altcoin Season, 25 or less Bitcoin Season. The widely quoted Blockchaincenter index uses 90 days instead.

Shows what share of the 50 largest altcoins outperformed Bitcoin over the past 30 days, the zone that share falls into, and the eight strongest altcoins over the same window. It is for holders and traders weighing how broad an altcoin rally or a Bitcoin-led phase is.

What you enter

• None; the page loads the top 100 coins by market cap with their 24-hour, 7-day and 30-day USD price changes (CoinGecko, cached about 2 minutes).
• Universe: the first 50 coins after removing BTC, stablecoins (USDT, USDC, DAI, TUSD, USDe, FDUSD, USDS, PYUSD, BUSD, USDD) and wrapped or staked tokens (WBTC, WETH, wstETH, stETH, WBETH, cbBTC, LBTC, sUSDe, weETH).
• Window: 30-day price change; if fewer than 20 of those 50 coins have a 30-day value, the page switches to the 7-day change.

What it shows

• The index from 0 to 100 on a bar running from yellow (Bitcoin side) through blue to purple (altcoin side)
• Zone label: Altcoin Season (75 or more), Bitcoin Season (25 or less) or Transition Zone (26 to 74), with a short comment line
• How many altcoins beat BTC out of those with data, and BTC's own change over the window used (30d or 7d)
• The top 8 altcoins by price change over the same window

How to use it

1. Open the page and wait for the market data to load.
2. Read the index and its zone label.
3. Check the count line, for example 30/48, and BTC's change, and confirm whether the window shown is 30d or 7d.
4. Look at the top 8 list to see whether the outperformance is broad or led by a few coins.
5. Check again over several days to see which way the index is moving.

Formula

Index = round(number of altcoins whose change > BTC's change / number of altcoins with data × 100). Change = 30-day % price change in USD, or 7-day % change if fewer than 20 of the 50 altcoins have a 30-day value. An altcoin whose change exactly equals BTC's does not count as beating it. Zones: index ≥ 75 Altcoin Season; index ≤ 25 Bitcoin Season; 26 to 74 Transition Zone.

Worked example

Hypothetical: BTC is up 10% over 30 days, 48 of the 50 altcoins have 30-day data, and 36 of them rose more than 10%. Index = 36 / 48 × 100 = 75, so the label is Altcoin Season. With 24 beating BTC the index is 24 / 48 × 100 = 50 (Transition Zone); with 12 it is 12 / 48 × 100 = 25 (Bitcoin Season).

How to read the result

• A high reading means most large altcoins did better than BTC over the window: broad breadth, not proof that any single coin is strong.
• A low reading means BTC beat most of the top 50, which typically happens while Bitcoin dominance is rising.
• The index is relative: in a falling market every coin can be down and the reading still be high if altcoins fell less than BTC.
• This radar uses a 30-day window, while the widely quoted Blockchaincenter Altcoin Season Index uses 90 days with the same 75 and 25 thresholds; the shorter window reacts faster and swings more, so the two numbers often differ.

Limits and cautions

• It counts how many coins beat BTC, not by how much: 50 coins each beating BTC by 1% and a handful doubling can produce similar readings.
• The top 50 changes as market caps move, and coins that dropped out of the list during the window are not counted.
• If the count line shows 0/0, market data is degraded and the index reading is not meaningful.
• A 30-day or 7-day window can flip quickly after a single large BTC move; read it as a description of the recent past.

Key terms

Altcoin season index

The share of large altcoins that outperformed Bitcoin over a set window, from 0 to 100. This radar counts the top 50 altcoins by market cap over the past 30 days; the Blockchaincenter index uses 90 days.

Altcoin Season

A reading of 75 or more: at least three quarters of the top 50 altcoins beat Bitcoin's price change over the window.

Bitcoin Season

A reading of 25 or less: Bitcoin beat at least three quarters of the top 50 altcoins over the window, which typically happens while Bitcoin dominance is rising.

Transition Zone

A reading from 26 to 74, where neither Bitcoin nor altcoins clearly dominate.

Altcoin universe

The first 50 coins by market cap after removing Bitcoin, stablecoins and wrapped or staked tokens, so that only genuine price competition with Bitcoin is counted.

Common questions

What is altcoin season?

A period when most large altcoins outperform Bitcoin. On this page it means at least 75% of the top 50 altcoins beat BTC's 30-day price change.

How is the Altcoin Season Index calculated?

Take the top 50 altcoins excluding stablecoins and wrapped tokens, count how many had a larger price change than BTC over the window, and divide by the number with data. This page uses 30 days; Blockchaincenter's index uses 90 days.

Why is this number different from the Blockchaincenter Altcoin Season Index?

The window differs (30 days here, 90 days there) and the exclusion lists and data sources are not identical. A 30-day window reacts faster, so the readings can be far apart.

Does a high altcoin season index mean altcoins will keep rising?

No. It describes how altcoins performed relative to BTC over the past window; it says nothing about future prices or about absolute gains.

Sources and update cadence

• Blockchaincenter — Altcoin Season Index — the widely quoted 90-day version: top 50 coins, 75 / 25 thresholds and history
• CoinGecko API — /coins/markets — market-cap ranking and 24h / 7d / 30d price changes this radar is computed from

Further reading on this site

• Altcoin Season Signals: Which Indicators Actually Work?
• Bitcoin Dominance Explained: The Capital-Rotation Compass
• Bitcoin Dominance: The Capital-Flow Gauge of Cycle Phases — and What Actually Triggers Altseason

Last reviewed: 2026-10-25