Altcoin season: how to tell when it starts

"Altcoin season" — or altseason — is the stretch of a market cycle when most altcoins grow faster than bitcoin. Everyone waits for it, and almost nobody catches the start: by the time it is obvious, a good part of the move is already done.

How the Altcoin Season Index defines it

The most quoted definition comes from the Altcoin Season Index by Blockchaincenter: it is altcoin season when 75% of the top 50 coins have outperformed bitcoin over the last 90 days. Stablecoins and wrapped or asset-backed tokens (WBTC, stETH and the like) are left out, because they only mirror something else. When 25% or fewer beat bitcoin, it is bitcoin season; everything in between is neither. CoinMarketCap publishes its own version of the index over the top 100 coins.

The index answers a fair question — are altcoins as a group beating bitcoin? — but it answers it late. A 90-day window needs weeks of outperformance before it crosses 75, so the index confirms an altcoin season rather than announces it.

Signals that move earlier

• Bitcoin dominance falling while bitcoin's price holds. Money is leaving bitcoin for something else. Use a dominance chart without stablecoins: the classic one also falls when money simply parks in USDT (why that matters).
• ETH/BTC rising. Ether gaining on bitcoin has often been the first link of the chain.
• TOTAL3 outpacing bitcoin. On TradingView, TOTAL3 is the market cap without bitcoin and ether, and TOTAL3ES leaves out stablecoins as well. If it grows faster than BTC, the move has reached the rest of the market.
• Breadth. Count how many coins on your watchlist are beating bitcoin over a month. A few runners is a sector story; most of the list is a season.
• Stablecoin share falling. Money coming out of stablecoins and into coins is fuel; money flowing back into stablecoins is the opposite.

None of these is a trigger on its own. Several pointing the same way say more than any single one.

Why "altcoin season" is often a sector season

Recent cycles have rarely lifted everything at once. More often one narrative — AI, memes, layer-2s, real-world assets — runs hard while the rest of the market stands still. An index over the top 50 can stay neutral through a sector rally that doubles a dozen coins. So when you ask "is it altseason?", also ask "in which sector?".

How the end usually looks

Altcoin seasons tend to end the way they peak — fast. Warning signs people watch:

• funding on altcoin perpetuals running hot for days, and new listings pumping on day one;
• bitcoin dominance turning back up while altcoins stop making new highs;
• small caps rising on thinning volume.

Money usually flows back into bitcoin and stablecoins faster than it came out.

What to do with this in a portfolio

An altcoin season is a market condition, not a plan. The useful questions are narrower: which of your coins have already made their move, which still have room, and how much of the portfolio sits in one narrative.

That is what the AxiPivot rotation engine works with. It compares the coins you hold — or the whole active pool in the global mode — and proposes pairs: what to sell and what to move into, with the gain of each pair. Swaps inside one sector earn less, so a portfolio drifting into a single narrative shows up early. The classic order — bitcoin, ether, large caps, small caps — is covered in the guide to capital rotation.

For analysis, not for trading. Nothing here is financial advice.