I've been watching the crypto market long enough to notice something fascinating about how altcoins behave in cycles. There's this phenomenon called altseason—or alt season if you prefer—where altcoins suddenly start outperforming Bitcoin in ways that seem almost predictable once you understand the pattern.

So what is altseason exactly? It's essentially that window in the market cycle when altcoins experience stronger growth than Bitcoin. Your BTC price might be climbing, but here's the key: Bitcoin's market dominance actually falls during this time. We're talking about periods where Bitcoin goes from owning like 96% of the total crypto market to suddenly controlling just 36%. When that shift happens, altcoins get their moment.

Looking back at history, we've only really seen two true global altseason events so far, even though we've been through three complete Bitcoin cycles. The first one didn't really count because the altcoin market was basically nonexistent—we're talking about a time when all altcoins combined were worth less than a billion dollars. Wild, right?

The first real altseason kicked off on March 1, 2017. Bitcoin dominance absolutely collapsed from around 96% down to 36% in less than a year. By January 5, 2018, the total altcoin market cap hit $470 billion. That's a 564x increase in about 310 days. The entire altcoin market went from pocket change to serious money.

Then we got another one in the next cycle. Starting from $225 billion in total altcoin value, Bitcoin dominance peaked around 73% on January 3, 2021, then began its slow descent. The TOTAL2 index—that's the total market cap of the top 125 coins excluding Bitcoin—eventually peaked on November 10, 2021, right when Bitcoin hit its cycle top. This second altseason lasted 309 days and added $1.5 trillion to the altcoin market. That's a 6.5x increase.

Here's where it gets interesting. Both of those altseason periods lasted almost exactly the same time—310 days and 309 days respectively. That's not coincidence. There's something deeper going on with market structure.

It turns out the Bitcoin halving events have this weird structural effect on cycles. In the previous cycle, the halving happened on July 9, 2016, and altseason started 235 days later on March 1, 2017. In the cycle after that, halving was May 11, 2020, and altseason began 237 days later on January 3, 2021. The pattern is almost eerily consistent.

If you apply that same 235-day offset to the most recent halving on April 19, 2024, you'd predict altseason starting around December 10, 2024. And if you add the typical 310-day altseason duration to that, you land on October 18, 2025. Using completely different analytical approaches—looking at price action, dominance metrics, and cycle timing—researchers kept arriving at the same target date. That's the kind of convergence that makes you sit up and pay attention.

We're now in March 2026, and the market is already well into what appears to be this predicted altseason window. Bitcoin's current market dominance sits around 55.29% with BTC trading around $67.83K. The structure seems to be playing out as the historical patterns suggested.

But here's what really matters: which projects actually perform during altseason? Looking at the coins that did well in 2020, most of them had parabolic moves in 2021. The pattern suggests that strong projects tend to dominate during altseason—it's not usually the dark horses that win, but the established players that already have momentum.

This year's top performers have been heavily weighted toward meme coins based on year-to-date returns. But if you're looking for more fundamental plays, the projects with real market cap above $1 billion in categories like Blockchain infrastructure, AI, and CeFi have been showing strength.

The takeaway from analyzing these altseason cycles is pretty clear: they're not random. They follow a structure tied to halving events and market dominance shifts. If the pattern holds, we should see this current altseason continue to develop through the rest of 2026. Whether it matches the explosive growth of previous cycles remains to be seen, but the structural setup is definitely there. The question now is which projects will be the ones that actually capture the gains when altseason truly accelerates.