How Long Did Altcoin Season Last: Timeline & Lessons

Published On: 2025-11-05

Prepared by Jameson Richman and our team of experts with over a decade of experience in cryptocurrency and digital asset analysis. Learn more about us.

How long did altcoin season last is a question traders, investors, and crypto analysts repeatedly ask when trying to understand past cycles and prepare for future ones. This article summarizes what “altcoin season” means, how to measure its start and end, historical examples, a step-by-step case study approach, reliable indicators to watch, practical trading strategies, and tools you can use to track altseason in real time.

What is “altcoin season”?

Altcoin season (often called “altseason”) refers to a period when alternative cryptocurrencies — any coin other than Bitcoin — significantly outperform Bitcoin in price gains and market capitalization growth. During these phases, investor appetite shifts away from Bitcoin dominance toward smaller-cap tokens, DeFi projects, NFTs, and memecoins. Altseason can be short and explosive (weeks) or prolonged and broad-based (months to over a year), depending on liquidity, macro factors, and market sentiment.

Common definitions and metrics

Because “altcoin season” is not a rigorously defined academic term, traders rely on measurable indicators to determine when it’s happening and how long it lasted. Below are the most commonly used metrics:

Bitcoin dominance — the percentage of total cryptocurrency market cap held by Bitcoin. When BTC dominance falls while total market cap rises, altcoins are typically gaining share. You can track this on platforms such as CoinMarketCap or CoinGecko.
Altcoins vs. BTC performance — percent of top 50–100 altcoins that outperform Bitcoin over fixed windows (30/60/90 days). A common rule-of-thumb used by some analytics sites: if 75% of top altcoins outperform BTC over 90 days, it’s altseason.
Altcoin market cap share — the absolute and relative market cap growth of altcoins vs. BTC.
Network activity and TVL — increases in DeFi total value locked (TVL), NFT volumes, and on-chain activity often accompany alt rallies.
Search and sentiment metrics — Google Trends, social volume, and crypto-specific fear & greed indexes can help time the enthusiasm stage.

For a refresher on cryptocurrency fundamentals, Wikipedia’s Cryptocurrency overview is a useful high-level resource: Cryptocurrency — Wikipedia.

How long did altcoin season last — historical overviews

Altseasons have taken different shapes across cycles. Below are three notable examples and approximate durations. Because markets are complex and data sources vary, the durations are approximate and meant to illustrate variability rather than fixed rules.

2017–2018: The first mainstream altseason (roughly November 2017 – January 2018)

The bull run of 2017 culminated in late 2017 and early 2018 with massive altcoin gains. Bitcoin’s price peaked in mid-December 2017 (around $19–20k), while hundreds of altcoins continued to spike into January 2018. Many ICO-era tokens saw parabolic returns.

Approximate altseason length: roughly 6–10 weeks of concentrated outperformance for many altcoins, though some smaller tokens continued their moves into early 2018.
Drivers: ICO speculation, retail FOMO, and limited supply on exchanges for many new tokens.

2020–2021: DeFi & NFT powered altseason (roughly January 2021 – May 2021)

The 2020–2021 cycle featured a broader, more institutional-friendly crypto market. While Bitcoin’s rally started in late 2020, altcoins accelerated in early 2021. Bitcoin dominance dropped sharply as DeFi, yield farming, and NFT narratives drew capital into alt markets.

Approximate altseason length: multiple months. For example, January–May 2021 saw sustained altcoin performance — some altcoins outperformed BTC for 3–5 months, others longer.
Drivers: explosion in DeFi TVL, NFT marketplaces, improved infrastructure (layer-1 & layer-2), and inflow of retail and institutional capital.

2023–2024: Post-winter alt surges (intermittent, varying durations)

After the 2022 crypto downturn, 2023 and parts of 2024 saw several concentrated alt rallies (including memecoin runs). These periods were generally shorter and more concentrated in memes or specific sectors (L2s, AI-related tokens).

Approximate altseason lengths: often a few weeks to a couple of months, but not as broad as 2021.
Drivers: renewed risk-on flows, speculative mania around certain narratives, and market structure changes.

These historical snapshots show that altseasons vary considerably in duration and intensity. The key takeaway: altseason length depends on market structure, liquidity, macro conditions, and new narratives attracting capital.

Measuring duration: a reproducible method

If you want to answer “how long did altcoin season last” for a specific cycle, use a reproducible method. Below is a step-by-step approach you can apply to any period.

Pick your timeframe. Define start and end dates you suspect encompass an altseason (e.g., Jan 1 to Jun 30, 2021).
Choose metrics to define the start and end. Common criteria include:
- Bitcoin dominance decline of X% from local peak (e.g., >5% drop).
- Percentage of top-100 altcoins outperforming BTC above a threshold (e.g., >70% outperforming over 30/60/90 days).
- Altcoins total market cap growth exceeding Bitcoin’s growth for Y consecutive weeks.
Gather data. Use historical BTC dominance charts (CoinMarketCap) and price histories for top altcoins (CoinGecko, CoinMarketCap, TradingView).
Apply the criteria. Mark the earliest date when criteria are met as the altseason start and the last date the criteria are met as the end.
Calculate duration. The time between these two dates is your measured altseason length.

Example: If BTC dominance fell from 70% to 60% between Feb 1 and Apr 1, while 80% of top-100 altcoins outperformed BTC over the same 60-day window, you could label that 60–90-day period as altseason, noting the caveats and data source.

Case study: Measuring the 2021 altseason (illustrative)

Using the reproducible method above (illustrative, not exhaustive):

Metric choice: BTC dominance drop >5% and >70% of top-100 altcoins outperforming BTC across a rolling 60-day window.
Observed pattern: BTC dominance dropped substantially from late December 2020 through May 2021. Many altcoins outperformed BTC during January–May 2021, particularly during March–May.
Estimated duration: roughly 3–5 months (March–May 2021 was the most concentrated alt outperformance window).

Because metrics and sources vary, other analysts may extend or shorten that window. The value is in consistent methodology rather than a single “official” number.

Key indicators and signals to watch in real time

To detect the start and end of future altseasons — and to manage positions — monitor these indicators:

BTC dominance chart: A sustained decline is a primary altseason signal.
Altcoin breadth: Percent of altcoins with positive returns vs. BTC across rolling windows (30/60/90 days).
DeFi TVL and on-chain activity: Rising TVL often precedes or accompanies alt rallies. Check DefiLlama for TVL stats: DefiLlama.
Exchange flows and liquidity: Increased deposits to centralized exchanges and stablecoin inflows show new buying power.
Volatility & correlation: Smaller assets showing reduced correlation and rising relative volatility indicate speculative rotation.
News and narrative trigger: Layer-2 launches, major protocol upgrades, or regulatory clarity often prompt sector-wide altcoin moves.
Search trends & social volume: Google Trends spikes for terms like “How to buy [token]” or “NFT” can reflect retail FOMO.

For technical setups, TradingView is the industry-standard charting platform; if you want to learn interface tips like displaying multiple charts, see this practical guide: How to show two charts in TradingView — 2025 Guide.

Trading strategies during an altseason

Altseasons present opportunities but also heightened risk. Below are actionable strategies and risk management tips:

1. Rotation strategy

Rotate profits from Bitcoin into high-conviction altcoins when BTC dominance declines and alt breadth expands. Use trailing stop losses and partial profit-taking to lock gains.

2. Momentum trading

Identify breakout altcoins with strong volume and relative strength indicators (RSI, MACD). Momentum trades can be swift — set tight risk limits and use position sizing to control downside.

3. Sector-focused investments

During narrative-led altseasons (e.g., DeFi or L2), focus on the strongest projects within that sector rather than random small-caps. This often reduces idiosyncratic risk.

4. Dollar-cost averaging & portfolio rebalancing

For longer-lasting altseasons, dollar-cost averaging into a basket of altcoins and rebalancing periodically can capture upside while managing risk.

5. Use of derivatives

Experienced traders can use futures and options for hedging or leveraged exposure. Be cautious: derivatives amplify both gains and losses.

Practical exchange options

If you plan to trade altcoins, consider established exchanges for liquidity and risk management. Here are links to popular platforms (this is not investment advice):

Register on Binance — wide altcoin selection and deep liquidity.
MEXC invite — broad token listings, often early access for new projects.
Bitget referral — futures and copy-trading features.
Bybit invite — derivatives-focused platform with growing alt listings.

Always enable two-factor authentication (2FA), understand withdrawal limits, and follow exchange-specific compliance rules. For region-specific legality questions (for example, Binance), see expert analyses such as this guide: Is Binance trading legal in Pakistan — 2025 Complete Guide.

Tools, dashboards, and charts to monitor altseason

Use a combination of on-chain dashboards, charting tools, and market data platforms:

TradingView — live charts, custom indicators, and multi-chart layouts. See tips for showing multiple charts here: How to show two charts in TradingView.
CoinMarketCap / CoinGecko — market cap, dominance, top movers, and historical snapshots.
DefiLlama — DeFi TVL and protocol rankings.
Glassnode / CryptoQuant — on-chain metrics for flows, exchange reserves, and derivatives data (paid tiers available).
Google Trends — track search interest spikes.
Social listening tools — LunarCRUSH, Santiment for social sentiment and on-chain signals.

If you’re investigating automated or copy-trading solutions during altseasons, review safety analysis and expert articles before onboarding. For example, this deep-dive discusses the safety profile of autopilot trading apps in 2025: Is Autopilot Trading App Safe in 2025 — In-Depth Expert Analysis.

Common mistakes during altseasons and how to avoid them

Chasing the top: Buying after a token triples without risk controls can lead to catastrophic drawdowns. Use staged entries and trailing stops.
Ignoring liquidity: Thinly traded altcoins may have wide spreads and slippage. Prioritize liquidity when sizing positions.
No exit plan: Plan profit-taking levels and stop-losses before entering trades; greed often erodes returns.
Overleverage: Leverage amplifies losses. In volatile altseasons, keep leverage conservative or avoid it entirely.
Poor project due diligence: Speculative narratives can be short-lived — check fundamentals (team, tokenomics, roadmap).

How long did altcoin season last? A concise answer

There is no single fixed answer to “how long did altcoin season last” — altseasons have ranged from a few weeks to several months, and in some cycles parts of the market remained in an alt-driven regime for over a year depending on the measurement method. Historically:

Late-2017 alt moves were intense but relatively short (weeks to a few months).
The 2021 altseason tied to DeFi/NFTs was broader and lasted several months (roughly early–mid 2021 for the concentrated phase).
Post-2022 recoveries produced shorter, narrative-driven alt rallies (weeks to a couple of months).

These durations depend on the definition you use: BTC dominance movements, altcoin breadth measures, or absolute alt market cap growth. The best practice is to define and measure consistently — then you can say with evidence how long any particular altseason lasted.

Practical checklist: How to measure altseason length for your research

Define your altseason criteria (BTC dominance threshold, breadth %, timeframe).
Collect data from reliable sources (CoinMarketCap, CoinGecko, TradingView, DefiLlama).
Apply a rolling-window analysis (30/60/90 days) to smooth noise.
Mark start and end dates based on when criteria are first and last satisfied.
Document assumptions and data sources for reproducibility.

Final thoughts

“How long did altcoin season last” is a valid and actionable research question — but it requires a clear, repeatable method to answer accurately. Altseasons can be fleeting or prolonged; the difference often boils down to liquidity, sector narratives, and macro tailwinds. By adopting a metric-driven approach (BTC dominance, alt breadth, market cap share), using robust tools (TradingView, CoinMarketCap, DefiLlama), and applying disciplined trading strategies and risk management, you can quantify past altseasons and position yourself to respond to new ones.

Remember: this article is educational and not financial advice. Always do your own research, consider consulting a licensed financial professional, and only trade amounts you can afford to lose.