Altcoin Season Index

How often is it actually Altcoin Season?

The strict "Altcoin Season" classification (index >= 75) is historically rare. Across 106 months of history since January 2018:

The market has spent roughly 4.1 times as many months in Bitcoin Season as in Altcoin Season (33 months vs 8). The asymmetry makes sense: for the index to reach 75, three quarters of the top 50 have to beat BTC at the same time, which only happens in broad rallies. Most "altcoin season" calls on social media refer to the wider Lean alt zone (50-74) rather than the strict 75+ threshold.

Is it Altcoin Season right now?

No. The Altcoin Season Index reads 66 as of 8 October 2026, which is classified as Lean alt. 33 of the 50 top altcoins evaluated have outperformed Bitcoin over the trailing 90 days, a period in which Bitcoin itself rose 29.2 percent. For an Altcoin Season classification (index >= 75), 75 percent of the top 50 alts would need to beat BTC over the same 90 days. The last month-end Altcoin Season reading was August 2022; the last Bitcoin Season reading was January 2026.

Longest Altcoin Season vs Bitcoin Season streaks

The longest Bitcoin Season spell ran 4 months and the longest Altcoin Season spell 4 months, so the difference is not in how long the spells last. It is in how often they happen: 14 separate Bitcoin Season spells since January 2018 against 4 Altcoin Season spells. That fits BTC's role as the crypto market's reserve asset: capital concentration in BTC is the usual state, with broad altcoin outperformance showing up only in specific cycle phases.

What is the Altcoin Season Index?

The Altcoin Season Index measures BTC-vs-alts rotation as a momentum metric over a defined recent window:

Altseason Index = (top 50 alts beating BTC over 90 days / total alts evaluated) × 100

The convention was popularised by BlockchainCenter around 2020 and has been adopted by Bitbo, Lookintobitcoin, and most major crypto analytics platforms. The index is bounded 0 to 100 by construction.

How to read the index

• Gradient bar at the top of the live index panel: shows the current value with the headline classification ("It IS Altcoin Season!", "It IS Bitcoin Season!", or "It is not Altcoin Season."). The marker line on the bar shows precisely where the index sits within the 0-100 range.
• Interpretation paragraph: plain-English translation of the current value into a cycle-phase read.
• Historical context table (right panel): months since the last Altcoin Season vs the last Bitcoin Season, average gap between season events, longest historical streak, average season length, and total months at each classification. Use this to anchor the current value against historical base rates.
• Interactive historical chart (below): hover any point for the exact index value, month, and classification. Toggle between Month and Year granularity. Fullscreen for analysis.

Classification bands

Methodology

1. Current reading. Twice a day the data pipeline pulls CoinMarketCap's latest listing of the top 100 coins by market capitalisation, removes Bitcoin and the excluded coins below, keeps the top 50 that remain, drops any listed less than 90 days ago, and counts how many have a 90-day price change above Bitcoin's. Index = outperformers / coins evaluated × 100, rounded to the nearest integer. The ratio is the same in USD or AUD, because a coin that beats BTC in one currency beats it in the other. If CoinMarketCap is unreachable, the pipeline falls back to CoinPaprika rankings with daily closes from Binance's public market data, which covers fewer coins (only those with a Binance USDT pair).
2. Monthly history. Every month from January 2018 is calculated from CoinMarketCap's historical snapshot for the last day of that month. The top 50 is taken as ranked on that day, so coins that later dropped out of the rankings are counted and today's leaders are not pushed back into months when they were small. Each coin's month-end price is compared with its price in the snapshot 90 days earlier; coins with no price 90 days earlier are left out. A few snapshots are incomplete (30 November 2020 is missing Polkadot, Uniswap, Cosmos and more than a dozen other top-50 coins), so each month-end snapshot is checked against the day before and the adjacent day is used where needed. The current month shows the latest live reading and is recalculated from the month-end snapshot once the month closes. Before September 2026 this chart used an approximate hand-built reconstruction for past months; it has been replaced by the calculation described here.
3. Exclusions. Stablecoins, wrapped and staked tokens (WBTC, stETH and similar) and tokenised gold (PAXG, XAUt) are removed using an explicit list plus CoinMarketCap's stablecoin, wrapped-token and tokenised-gold tags. The tags catch most new stablecoins as they climb into the top 100.
4. Window choice. 90 days is the BlockchainCenter convention; shorter windows (30 days) produce more volatile values, longer windows (180 days) smooth out short-cycle rotations. The 90-day choice balances responsiveness with noise.
5. Resilience. If a source is unreachable, the previous data file is kept unchanged. A past month that fails to calculate keeps its previous value and is retried on the next run.

Limitations

• Window-dependent. Changing the window from 90 days to 30 or 180 days produces different index values for the same date. The 90-day convention is the most-cited but is one of several reasonable choices.
• Top-50-dependent. Coins outside the top 50 can move significantly without affecting the index. A new memecoin pumping 1000 percent is invisible if it isn't yet in the top 50.
• Lagging. The index averages a trailing 90-day window. Rotation that has just started is barely visible; rotation that has run for 90 days appears at full intensity. The index confirms what has happened, not what is about to happen.
• Stablecoin definition is fuzzy. The exclusion list is maintained but new stablecoins enter the market regularly. CoinMarketCap's tags catch most of them, but edge cases (untagged pegged tokens, basket stables) may still slip through.
• Month-end sampling. History is one reading per month end, so a spell that started and finished inside a single month can be missed, and spell lengths are counted in whole months.
• Single dimension. The index captures breadth (how many alts beat BTC) but not magnitude (by how much). An Altcoin Season where alts beat BTC by 5 percent is classified the same as one where they beat BTC by 50 percent.

Related tools

• Bitcoin Dominance Chart - stock companion to this index; BTC market cap as % of total crypto, monthly from 2014.
• BTC Dominance vs Altcoin Season Index - how the two indicators relate, with divergence patterns and reading guide.
• Bitcoin Log Regression Bands (AUD) - long-run BTC fair value. Provides absolute price context for the rotation read.
• Bitcoin Rainbow Chart (AUD) - sentiment-labelled version of the log regression.
• Bitcoin Pi Cycle Top Indicator (AUD) - top-zone signal that often precedes a full Altcoin Season classification.
• Crypto CGT Calculator - apply the ATO 50 percent discount to any rotation that triggers a CGT event.
• Crypto Exit Strategy Ladder - build an Altseason-anchored exit ladder for any single crypto position.

Frequently asked questions

About the author

Govind Satoshi

Former Institutional Trader. Founder, SatoshiMacro.

Traded allocated institutional capital at a Sydney proprietary trading firm.