Understanding Bitcoin Dominance and Alt Season

You are watching the charts and Bitcoin has just hit a new high. You check your portfolio, expecting your other tokens to be up as well, but they have barely moved.

A few weeks later, Bitcoin slows down and starts trading sideways. Suddenly, those smaller tokens begin to double in value in a matter of days. That is the classic crypto market rotation playing out in real time.

To understand why this happens, it helps to know two core ideas: Bitcoin dominance and alt season.

What is Bitcoin dominance?

Bitcoin dominance tracks Bitcoin's share of the total cryptocurrency market.

It is calculated by dividing the market capitalisation of Bitcoin by the combined market capitalisation of all cryptocurrencies. The result is shown as a percentage.

Imagine the crypto market as a single pie. Bitcoin dominance tells you how large Bitcoin's slice is compared with everything else. If the total pie grows, but Bitcoin's slice grows faster than the rest, its dominance rises.

This metric is closely linked to market sentiment. When investors are nervous, or when a new cycle is just starting, many treat Bitcoin as a safer option compared with other digital assets. This move to relative safety often causes Bitcoin dominance to increase.

When investors feel confident, they usually look for higher returns in riskier altcoins. Capital shifts away from Bitcoin, and its dominance tends to fall.

What is an alt season?

Alt season is short for alternative cryptocurrency season. It describes a phase in the market where alternative coins, known as altcoins, see a strong rise in trading volumes, market interest and prices, and they outperform Bitcoin by a wide margin.

Traders sometimes use a simple guideline to decide whether an alt season is underway. Known as the 75 per cent rule, it suggests that an alt season is occurring if 75 per cent of the top 50 cryptocurrencies perform better than Bitcoin over a 90-day period.

During these phases, it is common to see daily double-digit percentage gains across completely unrelated tokens. This usually reflects extreme optimism and speculative behaviour.

How it works in practice

Crypto markets often move in cycles of capital rotation. Money tends to flow from larger, more established assets into smaller, riskier ones over time.

Here is how this cycle usually unfolds:

• Bitcoin takes the lead: Institutional and retail capital flows into Bitcoin first, pushing its price and dominance higher.
• Consolidation begins: Bitcoin reaches a local peak and starts to trade sideways as early investors take profits and new buyers hesitate.
• Capital rotates: Investors searching for higher returns shift profits out of Bitcoin and into large-cap altcoins such as Ethereum or Solana.
• The season peaks: Money eventually spills into mid-cap and low-cap tokens, leading to a fast, broad rally in prices.

There have been multiple times that this pattern has played out.

In January 2018, after a huge run in Bitcoin, its dominance dropped from over 60 per cent to around 32 per cent. At the same time, many altcoins hit all-time highs.

In 2020, the market went through a sector-based rotation known as DeFi Summer. Decentralised finance tokens posted strong gains while Bitcoin stayed relatively quiet.

More recent cycles have become a bit more fragmented. The introduction of institutional capital through products such as spot ETFs means larger investors often prefer major assets. Instead of every token rising together, there’s now shorter, focused mini-seasons. This is where specific sectors, for example artificial intelligence tokens or meme coins, rally on their own.

Risks and how to stay safe

Alt seasons can produce some of the highest returns available in crypto. They are also some of the riskiest periods to be in the market.

One key warning sign is extreme market euphoria. If sentiment indicators show high levels of greed and lesser-known tokens are rising quickly without any clear fundamental progress, the market may be overheating.

Alt seasons rarely last long. When momentum fades and liquidity dries up, altcoins can fall very sharply. It is not unusual for some tokens to lose 90 per cent or more of their value against Bitcoin over a long downturn.

To manage risk, it helps to accept that simply holding any altcoin does not guarantee profit. Projects with real users and clear utility are increasingly separating themselves from older networks that have little activity.

Before buying, take time to research the underlying technology, the team, the token’s use case and actual user adoption. Try to avoid placing money into tokens solely because they are trending on social media or being promoted by influencers.

Why Bitcoin dominance and alt season matter

When you zoom out, the interaction between Bitcoin dominance and alt season offers a simple way to understand human behaviour and risk appetite across the crypto market.

Tracking these measures can help you work out if there might be a broader market cycle. For example, a period of rising Bitcoin dominance can signal caution, while a strong drop in dominance may suggest that capital is rotating into higher-risk assets.

When money flows out of Bitcoin and into alternative networks, it can support funding for new technologies, decentralised applications and blockchain infrastructure. This is often where innovation happens, although it also comes with greater risk.

By understanding these patterns, you can better judge whether the market feels like a period of calmer accumulation or a phase of speculative excess. That knowledge can help you make more informed decisions about your own digital asset strategy.