Altcoin Season Explained: How to Spot the Rotation

What Is Altcoin Season?

Altcoin season is a period when altcoins — cryptocurrencies other than Bitcoin — broadly outperform Bitcoin. It is a relative concept, not a directional one. Altcoin season can happen while the whole market is falling, as long as altcoins fall less than Bitcoin. Likewise, Bitcoin can be leading a roaring bull market, which would not be altcoin season even though everything is up.

The question matters because the two regimes call for different positioning. When Bitcoin leads, holding BTC is often the safer, stronger play. When altcoins lead, capital is flowing down the risk curve and altcoin holders tend to outperform.

How the Altcoin Season Index Works

The Altcoin Season Index turns the question into a single number from 0 to 100. The methodology is:

1. Take the top 50 coins by market capitalisation.
2. Exclude stablecoins (they hold a fixed value) and wrapped or staked tokens (they track another asset).
3. Count how many of the remaining coins outperformed Bitcoin over a chosen window.
4. Express that count as a percentage — that is the index.

If Bitcoin rose 10% over the window and 40 of the 50 coins rose more than that, the index reads 80. The widely used thresholds are:

A Note on the Time Window

The best-known version of this index uses a 90-day window. Because that window is not always available in a single data request, our tool lets you switch between 7-day, 30-day, and 1-year views instead, with 30 days as the closest practical proxy for the classic index. The 7-day view is noisy and reacts to single rallies; the 1-year view captures the bigger rotation. Comparing windows before concluding a season has begun is good practice.

How Capital Rotates Through the Market

Altcoin seasons rarely appear from nowhere. There is a familiar rotation pattern in crypto bull markets:

1. Bitcoin leads first. New money enters the safest, most liquid asset — Bitcoin — and BTC dominance rises.
2. Large-cap altcoins follow. As Bitcoin gains stall, profits rotate into Ethereum and other large caps.
3. The rotation moves down the risk curve. Mid-caps and eventually small-caps catch a bid as risk appetite peaks.

A rising Altcoin Season Index late in a cycle is often read as this risk appetite expanding. It usually coincides with falling Bitcoin dominance — the two are effectively two views of the same rotation, which is why reading them together is powerful.

How to Read the Signal Without Getting Fooled

Remember it is relative, not directional

A high reading does not mean prices are up — only that altcoins are beating Bitcoin. Always check the Bitcoin benchmark alongside the gauge so you know whether the whole market is rising or falling.

Watch the threshold crossings

The signal is in decisively crossing 75 into altcoin season or 25 into bitcoin season. A reading hovering at 50 is telling you there is no clear leadership — that is information, not indecision.

Pair it with Bitcoin dominance and sentiment

Altcoin season, falling dominance, and rising greed on the Fear & Greed Index tend to arrive together late in a cycle. Reading them side by side confirms whether capital is genuinely rotating out of Bitcoin.

Do not treat it as a trade trigger

Rotation gauges describe the crowd, not the future. Fifty coins is also a narrow slice of a market with thousands, so the index is context for relative strength, not a standalone entry or exit.

Frequently Asked Questions

What defines an altcoin?

Any cryptocurrency other than Bitcoin. In the context of this index, stablecoins and wrapped or staked tokens are excluded, so "altcoins" here means genuine, independently trading assets.

Why are stablecoins excluded?

Stablecoins are designed to hold a fixed value and wrapped tokens simply track another asset, so including them in a "did it beat Bitcoin" comparison would be meaningless. Removing them leaves a cleaner picture of real altcoin performance.

Does altcoin season mean I should sell Bitcoin?

Not by itself. The index describes where relative strength currently sits, not what will happen next. Use it as one input alongside your own research and risk management.

Combine it with market sentiment on the Crypto Fear & Greed Index for a fuller read on where the cycle stands.