Altseason Explained: The Complete Guide to This Cryptocurrency Phenomenon

An altseason is one of the most intriguing concepts in the cryptocurrency market, marking periods when altcoins experience much stronger gains than Bitcoin. This cycle can mean huge opportunities for investors, but understanding when it occurs and how it works is essential. In this article, we’ll explore what altseason is, its historical patterns, and what we can expect for upcoming market cycles.

What Is Altseason and Why Does It Matter

Altseason, or altcoin season, refers to a specific period in the cryptocurrency market cycle when altcoins (all cryptocurrencies except Bitcoin) show more aggressive growth than Bitcoin itself. During these times, while BTC’s price continues to rise, its market dominance (BTC.D) drops significantly, indicating that capital is moving into other assets.

The technical definition is clear: altseason begins when Bitcoin’s dominance hits a local peak and ends when the TOTAL2 index — which measures the total market value of the top 125 cryptocurrencies excluding Bitcoin — hits a new all-time high. To put it in context, Bitcoin currently holds a market share of 55.47%, with a price of $69.97K, demonstrating significant growth since the early market cycles.

History: How Two Altseasons Shaped the Cryptocurrency Market

To fully understand the altseason phenomenon, we need to look back at previous cycles. It’s fascinating to note that only two significant altseasons have occurred across three complete Bitcoin cycles. This mainly happened because, in the early cycles, the altcoin market was virtually nonexistent.

The First Major Altseason (2017-2018)

The first strong wave of altcoin growth began on March 1, 2017. At that time, Bitcoin’s dominance was around 96%, a drastically different scenario from today. In less than a year, specifically by January 5, 2018, this dominance fell to about 36% — a decrease of nearly 60 percentage points. This massive capital shift resulted in the total market cap of altcoins reaching an impressive $470 billion.

The first altseason lasted 310 days, during which the TOTAL2 index grew extraordinarily: an increase of 56,425%, or 564 times. These numbers show the magnitude of growth that can occur during these periods.

The Second Altseason (2020-2021)

The subsequent cycle brought the second global altseason during the 2020-2021 boom. Starting with a market cap of $225 billion in altcoins, Bitcoin’s dominance dropped to 73%. On January 3, 2021, this dominance began to decline, leading to a peak in the TOTAL2 index on November 10, 2021, coinciding with Bitcoin’s price peak.

This second altseason lasted 309 days, accumulating a growth of $1.5 trillion — a 650% increase, or 6.5x. The most notable? Both altseasons from different cycles lasted almost the same period: 310 days in the first, 309 in the second. This coincidence suggested deep patterns governing these cycles.

The Magic of Dates: Halving Cycles and Altseason Patterns

A particularly revealing discovery emerged when analyzing the timing of altseasons in relation to Bitcoin halving events. Previous studies showed that halvings occur consistently about 62% into each full cycle.

What’s even more impressive is that both global altseasons started within the same timeframe after their respective halvings:

• Cycle 2: Halving on July 9, 2016 → Altseason began 235 days later, on March 1, 2017
• Cycle 3: Halving on May 11, 2020 → Altseason began 237 days later, on January 3, 2021

This remarkable synchronization between these seemingly independent events suggests that halvings exert a deep structural influence on when altseasons start and how they develop.

When to Expect the Next Altseason and Its Implications

Based on these consistent patterns, analysts applied the same methodology to the current cycle. Bitcoin’s halving occurred on April 19, 2024. Adding 235 days to this date points to December 10, 2024, as the inflection point when Bitcoin’s dominance should reach its local peak, potentially marking the start of the next altseason.

Applying the typical duration observed in previous altseasons (310 days), we arrive at October 18, 2025, as the expected peak date for both Bitcoin and the TOTAL2 index. Combining two independent analytical methods — price pattern analysis and dominance structure — the same date emerged: October 18, 2025.

It’s important to emphasize that these are not guesses or traditional predictions but the result of objective analysis of market cycle structures. Past cycle patterns do not guarantee exact repetition, so these dates serve more as reference points than definitive forecasts.

Which Altcoins Lead During Altseason

An equally important question is: which projects perform best during these periods? Analyzing the top 10 projects in terms of performance in the previous cycle revealed a notable trend — coins that showed strong performance in the third year of each cycle (2020 in the previous case) tended to exhibit parabolic moves in the peak year (2021).

This suggests that altcoins gaining traction during the intermediate years of the four-year Bitcoin cycles often become the biggest winners during the actual altseason. Investors monitoring these entry and exit patterns look to identify which projects are gaining genuine adoption well before the altseason intensifies.

Volatility during altseason presents significant risk but also extraordinary opportunities. Projects with solid fundamentals and growing adoption tend to perform better, while speculative altcoins face higher correction risks when risk appetite diminishes.