Altseason

An altseason (short for "altcoin season") is a phase of the cryptocurrency market cycle during which alternative cryptocurrencies — all digital assets other than Bitcoin, collectively called "altcoins" — rise in price more aggressively than Bitcoin and, in aggregate, outperform it.^[1]​^[2]

The term describes a shift in investor focus in which capital rotates away from Bitcoin and into altcoins, so that Bitcoin's growth slows in relative terms even though its price does not necessarily fall.^[1]

Altseasons are characterized by large gains and high volatility, and they typically unfold over a relatively brief window of weeks or months before altcoin prices can retreat as quickly as they rose.^[3]​

How It Works

The mechanism behind an altseason begins with Bitcoin. After a strong rally, Bitcoin often stabilizes or trades sideways, and this stagnation prompts investors to swap Bitcoin for altcoins, reducing Bitcoin's share of the total crypto market capitalization.^[3]

As altcoin prices and altcoin-season indices trend upward, fear of missing out — commonly abbreviated FOMO — draws in further investment, creating a cascading effect that amplifies altcoin price rises for a limited period.^[3]

During bullish market conditions, investors with larger pools of capital become more willing to allocate to riskier assets, and this optimism feeds the rotation.^[1]​

​Trust Wallet identifies three core contributing factors: bullish market sentiment that pushes investors toward riskier assets; developments within the altcoin space itself, such as new project launches, platform upgrades, and innovative solutions; and decreasing Bitcoin dominance, in which the combined market value of altcoins comes to represent a larger share of the total market.^[1]

The company offers a localized example: a highly anticipated launch of a decentralized finance (DeFi) protocol on an altcoin blockchain can attract significant investment and drive that coin's price up, producing a narrower rally even outside a full market-wide altseason.^[1]​

More recent analyses stress the role of liquidity rather than a simple Bitcoin-to-altcoin rotation. Ki Young Ju, chief executive of the analytics firm CryptoQuant, has argued that altcoin trading volume against stablecoin pairs and rising stablecoin liquidity — through assets such as Tether (USDT) and USD Coin (USDC) — now play a critical role in driving altcoin seasons, describing stablecoins as "the backbone of modern altcoin markets" and increasing stablecoin liquidity as "fostering broader altcoin adoption."^[2]​

Indicators

The most commonly cited signal is the Bitcoin Dominance Index, which measures Bitcoin's market capitalization as a share of the total crypto market. A sustained decline in this metric, combined with rising altcoin prices, is treated as a strong sign an altseason may be forming; Trust Wallet and KuCoin both note that altseason often occurs when Bitcoin dominance falls below 50%.^[1]​^[2]

The analyst Rekt Capital regards Bitcoin dominance as a critical forecasting metric, observing that a sharp decline below 50% has historically been a reliable altseason signal.^[2] For the current cycle, some analysts have instead flagged a confirmed break below 55% Bitcoin dominance as the key inflection threshold, arguing that a sustained hold below that level is needed to confirm a broad rotation.^[3]​

A second widely used tool is Blockchain Center's Altseason Index, which measures the performance of the top 50 altcoins relative to Bitcoin; a reading above 75 is interpreted as indicating altseason.^[2] Analysts caution, however, that the index is reactionary and may register an altseason only after it has already begun.^[3]

Additional signals include a rising ETH/BTC ratio, rising altcoin trading volumes — particularly in altcoin-stablecoin pairs — social-media trends such as hashtags and influencer discussion that signal retail interest, and a broad shift in market sentiment from fear to greed.^[2]​^[3]

Every source emphasizes that these indicators are not foolproof and are best combined with broader context.^[1]​

Historical Altseasons

The first significant wave of altcoin growth began on March 1, 2017, when Bitcoin dominance stood at roughly 96%; within less than a year, by January 5, 2018, dominance had fallen to about 36%, meaning Bitcoin ceded roughly 60% of its market share to altcoins.

The combined altcoin market capitalization — tracked by the TOTAL2 index, which measures the market cap of the top 125 coins excluding Bitcoin — reached about $470 billion. That first major altseason lasted 310 days and represented an increase of around $470 billion in TOTAL2, described as a 56,425% rise, or roughly 564 times its starting value.^[4]

​KuCoin dates a similar period from late 2017 to early 2018, reporting that Bitcoin dominance fell from 87% to 32% while the total crypto market cap rose from $30 billion to over $600 billion before ending amid regulatory crackdowns and failed projects.^[2]

​Tangem reports that Bitcoin's own price fell from a then-record high above $20,000 to below $6,000 within a few months as the episode unwound.^[3]​

The 2020–2021 cycle brought the second observed global altseason.

Binance's analysis reports that Bitcoin dominance peaked at around 73% and began a slow decline on January 3, 2021, and that the TOTAL2 index peaked on November 10, 2021, coinciding exactly with Bitcoin's own price peak. This altseason lasted 309 days — almost identical to the first — and saw TOTAL2 rise by about $1.5 trillion, a 650% increase.^[4]

KuCoin reports that during 2021 Bitcoin dominance fell from 70% to 38%, altcoins' market share rose from 30% to 62%, and the total market cap reached an all-time high of over $3 trillion, in a period marked by booms in DeFi, NFTs, and memecoins.^[2]

Tangem notes the Altseason Index hit 98 on April 16, 2021, and links the era to the coronavirus pandemic, the rise of meme coins such as Dogecoin and Shiba Inu, and NFTs.^[3]​

The 2023–2025 period is described as featuring several strong phases of altcoin outperformance that did not match the breadth or duration of 2017 or 2021.

KuCoin attributes bullish sentiment across late 2023 and mid-2024 to optimism around the April 2024 Bitcoin halving and the prospect of spot Ethereum exchange-traded funds (ETFs), and reports rallies in altcoins including Arweave, JasmyCoin, dogwifhat, Worldcoin, and Fetch.ai, alongside sector-specific rallies in artificial-intelligence tokens such as Render and Akash Network — with claimed surges exceeding 1,000% — GameFi platforms ImmutableX and Ronin, and memecoins.^[2]

The Solana ecosystem is singled out for a memecoin boom driven by launch platforms such as pump.fun, producing parabolic runs in tokens including WIF and BONK and, later, celebrity

• and AI-themed memecoins; KuCoin reports Solana's token rose 945% during the period, reversing an earlier "dead-chain" reputation.^[3]​^[2]​

Risks

Every source that discusses altseason pairs its upside with substantial risk.

​Altcoins are more volatile than Bitcoin and present high-risk, high-reward scenarios in which prices can fall as fast as they rise.^[3]​^[1] KuCoin catalogs additional hazards: higher trading costs from wide price spreads in illiquid altcoin markets, hype and speculation inflating valuations, scams and "rug pulls" in which developers abandon a project after raising funds, pump-and-dump schemes, and regulatory changes that can disrupt markets.^[2]

Regulation has cut both ways historically: crackdowns on initial coin offerings (ICOs) in late 2018 and stricter exchange guidelines increased volatility and dampened altseason fervor, while the approval of spot Bitcoin ETFs by the U.S. Securities and Exchange Commission encouraged institutional investment.^[2]

The analyst Doctor Profit summarized the tension: "Altseason is thrilling but requires discipline. Without proper risk management, gains can quickly turn into losses."^[2]​