How is the altcoin season index calculated?

It's the share of the top altcoins that outperformed Bitcoin over a set lookback (typically 90 days), scaled to 0–100. Above ~75 is 'altcoin season'; below ~25 is 'Bitcoin season.'

Altcoin Season Calculator

BTC dominance tells you whether money is flowing into Bitcoin or altcoins. Enter current BTC.D to get signal.

BTC Dominance (%)

Current BTC.D — find on TradingView: TOTAL2/TOTAL

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BTC Dominance Guide

< 40%Strong alt season — aggressive alt exposure, take profits in BTC

40–47%Alt season — alts outperforming, rotate from BTC to quality alts

47–52%Neutral — mixed signals, selective exposure

52–58%BTC season — BTC outperforming, reduce alt exposure

> 58%Deep BTC season / bear — hold BTC or stables, avoid alts

Your position sizing

Portfolio ($)

Suggested BTC %

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Suggested Alts %

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How to use this calculator

Enter the current Bitcoin dominance (BTC's share of total crypto market cap) — check any market-cap tracker for the live figure.

Read the signal: dominance under ~47% tends to mean alts are gaining share from BTC; above ~52% tends to mean capital is concentrating back into Bitcoin.

Use it as market context, not a trade signal — it tells you the regime, not the entry.

The theory behind it

This tool uses Bitcoin dominance — BTC's share of total crypto market cap — as the regime gauge. When dominance falls, altcoins as a group are growing faster than Bitcoin: capital is rotating out of BTC and into alts, the classic 'altseason.' When dominance climbs, alts are bleeding market share back to Bitcoin. It's a regime gauge: it tells you whether the environment favours holding BTC or rotating into higher-beta alts, but it says nothing about any single coin's entry.

Frequently asked questions

What is altcoin season?

Altcoin season is a market phase where most altcoins outperform Bitcoin, usually driven by capital rotating from BTC into higher-risk alts. It's commonly tracked through falling Bitcoin dominance, since BTC losing market-cap share while the total market grows is what a broad alt rotation looks like.

How does this calculator read Bitcoin dominance?

Below 40% dominance: strong alt season. 40-47%: alt season. 47-52%: neutral/mixed. 52-58%: BTC season. Above 58%: deep BTC season. These bands are a simplified heuristic, not an official index — treat the labels as regime context, not a precise trigger.

Should I buy altcoins during altseason?

Altseason indicates a favourable regime for alts but is not an entry signal for any specific coin, and it often peaks near cycle tops. Use it as context alongside proper position sizing and risk management, not as a reason to abandon discipline.

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