How is the index computed?

By comparing real 90-day price performance of top coins against Bitcoin's own, then measuring what share are ahead.

No. CoinGecko's public API is free and key-less.

It's an independent computation using real market data, following the same widely used community methodology.

Yes — free, no download, in your browser.

Why are stablecoins left out?

They are designed to hold a steady price, so they cannot outperform Bitcoin in a meaningful sense. Asset-backed tokens such as wrapped bitcoin are excluded for a similar reason, and including either would distort the share.

Does the index forecast what comes next?

No. It describes the last 90 days, and a high or low reading carries no guarantee about the following weeks.

Altcoin Season Index Screensaver

The Altcoin Season Index screensaver computes a live index from real top-coin price performance, showing what share of major altcoins are currently outperforming Bitcoin — drawn key-less from CoinGecko. It's free, runs in your browser, and ESC exits.

How the Altcoin Season Index screensaver works

The saver fetches real recent price performance for the top coins by market cap from CoinGecko, with no key required.

Each coin's real 90-day performance is compared against Bitcoin's own.

The index shows what percentage of coins are genuinely beating Bitcoin right now.

A gauge reads from "Bitcoin season" to "Altcoin season" based on that real percentage.

Defining an altcoin season

An altcoin is any cryptocurrency other than Bitcoin. In market commentary an altcoin season is a stretch when many of these coins rise faster than Bitcoin does, often during a speculative phase. There is no formal definition. The metric used here follows a popular convention published by the Blockchain Center: take the top 50 coins by market cap and count how many outperformed Bitcoin over the previous 90 days.

On the Blockchain Center index, a reading of 75 percent or more means altcoin season, 25 percent or less means bitcoin season, and the range between is neutral. These cut-offs are conventions rather than laws, and other providers choose different universes, windows and exclusions. The Blockchain Center leaves out stablecoins and asset-backed tokens such as wrapped bitcoin, because they track another asset and cannot meaningfully outperform it.

The figure compares relative, not absolute, performance. Bitcoin can fall and still lead if the others fall more, and altcoins can win in a bear market for a few weeks. It also says nothing about which coins to buy or when to buy or sell. As a backward-looking ratio over a long window, it lags turning points, and the result depends on which coins fall within the top group.

A worked example

When the index reads high, most tracked coins have real recent gains outpacing Bitcoin's own — a genuine "altcoin season" reading, not a fixed label.

Settings & tips

Accent recolours the gauge.
This mirrors a well-known community metric, computed independently from real market data.
A high reading doesn't guarantee it continues — it's a snapshot, not a forecast.

Frequently asked questions

How is the index computed?: By comparing real 90-day price performance of top coins against Bitcoin's own, then measuring what share are ahead.
Is a key needed?: No. CoinGecko's public API is free and key-less.
Is this official?: It's an independent computation using real market data, following the same widely used community methodology.
Is it free?: Yes — free, no download, in your browser.
Why are stablecoins left out?: They are designed to hold a steady price, so they cannot outperform Bitcoin in a meaningful sense. Asset-backed tokens such as wrapped bitcoin are excluded for a similar reason, and including either would distort the share.
Does the index forecast what comes next?: No. It describes the last 90 days, and a high or low reading carries no guarantee about the following weeks.

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