Analytics · Altcoins
The Altcoin Season Index, explained
A 0–100 daily read on whether the market is tilted toward Bitcoin or the rest of it — published by CoinGlass, served here unchanged, with two lines of our own drawn across it at 20 and 80.
- Scale
- 0–100
- Source
- CoinGlass
- History
- Since Apr 2017
- Season lines
- 20 / 80
Bitcoin season to altcoin season
their published daily index
~3,400 daily points
ours, not the source's
What is the Altcoin Season Index?
A single number from 0 to 100 answering one question: right now, is the altcoin market outrunning Bitcoin or falling behind it? High means altcoins are the stronger side of the trade. Low means Bitcoin is.
That is the whole construct. There is no basket of smaller indicators underneath it and no scoring of our own — one published daily series, charted, with two thresholds marked on it.
Where the number comes from
We don't calculate this index. CoinGlass publishes the 0–100 value daily, for the whole history back to 2017, and we chart it exactly as they publish it.
What we add is the frame around it: the current reading, the average, the high, the low, the range of dates covered, and the two season lines drawn across the series. The number itself is never reweighted, blended or overridden by a model of ours.
How the scale is read
Three labels, two cut points:
- 80 and above · Altcoin Season — altcoin euphoria, and the high-risk end of this chart
- 20 and below · Bitcoin Season — Bitcoin leading, and where the case for buying altcoins is strongest
- Everything between · Neutral — sixty points of it
Those thresholds are ours, not part of what CoinGlass publishes. The same two levels set the season named on a given day and the shading drawn under it, so the two always agree.
Note the direction, because it runs opposite to most risk readings here: high is the dangerous end. The line is coloured on the same heat scale as our other charts — cold blue at the bottom of the range, through amber, to red at the top — and only the two extremes are shaded: blue below 20, red above 80.
What to keep in mind
A single published series everyone can see is easier to reason about than a blend of hidden ingredients. Four things are worth knowing before you read it.
Neutral covers 60 of the 100 points
Anything above 20 and below 80 reads as Neutral — three-fifths of the scale under one label. A move from 35 to 65 is a real change in what the market is doing, and the label sits still through all of it. The labels mark the two extremes; between them, read the number.
CoinGlass publishes the number, we publish the chart
CoinGlass calculates the index and publishes it daily. We chart their series as it stands, alongside the current reading, the average, the high, the low and the dates covered. Nothing is reweighted or recalculated, so their method and any revisions they make carry straight through.
The 20 and 80 lines are ours
CoinGlass publishes a number, not a season. The two thresholds, the three labels — Bitcoin Season, Neutral, Altcoin Season — and the shading under the line are our reading of their series. Where those lines sit is what decides which days count as a season at all.
It measures tilt, not timing
A reading is a snapshot of relative strength between Bitcoin and the rest of the market right now, not a forecast. It can sit above 80 for weeks or unwind in days, and the level tells you nothing about which altcoin benefits or how long the tilt holds.
The number belongs to CoinGlass. The point where Neutral stops being neutral belongs to us.
How do you read the chart?
Watch the number, not the label. With sixty of the hundred points reading Neutral, the label barely moves. A climb from the low 30s to the high 60s is the whole story, and the label sits still through all of it.
Smooth the line when the daily jumps get distracting. The chart draws the daily index by default and offers 7-day and 30-day averages instead. Colour, shading and tooltip all follow whichever version is on screen, so a smoothed line still matches the zones drawn under it.
There is nothing to rescale: the index only ever runs from 0 to 100, so the vertical axis stays fixed at 0–100 whatever the market is doing.
Where it fits
This answers one question: is the market rewarding Bitcoin or the rest of the field right now? It says nothing about which altcoin, whether the move is justified, or how long the reading holds.
For a second opinion drawn from different data, read the Altcoin Strength Index, which measures altcoin momentum against Bitcoin from figures we maintain ourselves rather than from CoinGlass. Two independent sources agreeing is worth more than either one on its own.
Common questions
What is the Altcoin Season Index?
A 0-100 daily reading of how the altcoin market is performing against Bitcoin. High values mean altcoins are outrunning Bitcoin; low values mean Bitcoin is the stronger asset. CoinGlass publishes the number and we chart it.
Does Blockchain Decoded calculate this index?
No. CoinGlass publishes the 0-100 value and we chart it as it stands, adding the current reading, the average, the high, the low, the dates covered and the season label. The number itself is theirs.
What do the readings mean?
80 and above is Altcoin Season, 20 and below is Bitcoin Season, and everything between is Neutral. The same two levels set both the label and the shading, so the season named on a given day always matches the zone it sits in.
How far back does the data go?
CoinGlass publishes it daily back to April 2017 — roughly 3,400 points, and the chart carries the whole run.
Why is the neutral band so wide?
Because the labels are reserved for the extremes — 20 and below, 80 and above. That leaves 60 of the 100 points reading Neutral, which is where the number itself does the work: a climb from the low 30s to the high 60s is a real shift, even though the label never changes.
Does a high reading mean you should buy altcoins?
It reads the other way round here. A high index is altcoin euphoria — the high-risk end of this chart, shaded red — and a low index is where the case for buying altcoins is strongest. Either way it measures which side is currently stronger, not what happens next, and it says nothing about which altcoin.
Related guides
Others in market structure — How much borrowed money is in the market, which way bets are leaning, and where money is moving.
- Altcoin Strength IndexA weekly 0–100 score for altcoins against Bitcoin, where 0 means historically cheap and 100 historically expensive.
- Bull Market ProgressHow far roughly thirty cycle-peak indicators have travelled toward their historical top readings.
- Funding RateWhat leveraged traders pay to hold their positions — the cost of crowd consensus.
- Open InterestHow much leverage is outstanding across futures venues, and which exchanges hold it.
- LiquidationsWhere leveraged positions were forcibly closed, long against short.
Every indicator we track — the full glossary.
See where it stands right now
The index is published daily by CoinGlass. The chart page gives you the full daily series back to 2017 with both zones shaded, a daily / 7-day / 30-day smoothing toggle, the current reading in the control bar and the season named on every point you hover.