#AltcoinSeasonLoading

Altcoin season occurs when the market capitalization of altcoins increases significantly relative to Bitcoin's market capitalization. This often translates to many altcoins experiencing rapid price increases.  
It's generally characterized by a decrease in Bitcoin's dominance (BTC.D), which is the percentage of the total cryptocurrency market cap held by Bitcoin. When Bitcoin's dominance drops, it suggests that capital is flowing into altcoins.  
Some define altcoin season as a period when a significant percentage (e.g., 75%) of the top 50 altcoins outperform Bitcoin over a specific timeframe (e.g., 90 days).

Historical Context:

Past altcoin seasons have often followed significant Bitcoin bull runs where Bitcoin's price stabilizes or moves sideways, prompting investors to seek higher returns in the more volatile altcoin market.
Notable altcoin seasons occurred in:

Late 2017 to early 2018: Following Bitcoin's surge to $20,000, many altcoins saw explosive growth, fueled by the ICO boom. Bitcoin dominance dropped significantly.  
December 2020 to April 2021: Amid the COVID-19 pandemic, altcoins rallied, driven by DeFi innovations, NFT mania, and increased retail interest. Bitcoin dominance again saw a substantial decline.