Sector Dominance: how big is each sector in the altcoin market?

Sector Dominance answers one question: how much of the altcoin market is a given sector? Pick a sector, such as memecoins, and the page shows that share as a line over time, so you can see whether the sector is taking a bigger or a smaller part of the altcoin market than before. You can overlay up to four sectors to compare them.

The altcoin market here means the 125 (or 300) largest coins by market cap, without Bitcoin, Ethereum, stablecoins, wrapped or staked copies of other coins, and tokenized real-world assets. A sector sits inside that market, so its share can never be above 100%. Sectors overlap: a coin can belong to more than one, so the shares of different sectors do not add up to 100%.

The headline number is the latest share of the first sector you selected. The line shows the same number for earlier days. A rising line means the sector is growing faster than the rest of the altcoin market, or the rest is shrinking. A falling line means the opposite.

Hover over the chart (or use the arrow keys) to see one day: each sector's share, its market cap and the altcoin market cap. Hold Ctrl and scroll to zoom, drag to pan, double-click to reset; a plain scroll over the chart just scrolls the page. When you overlay several sectors, 'Fit' scales every line to its own peak so small sectors stay readable; 'True share' shows the real sizes on one axis.

Under each sector in the heatmap you see the largest coins that make up its share on the latest measured day; click that line to open the full list with each coin's part of the sector and its market cap. A label such as '2 coins' or 'ZEC-driven' (one coin is more than half the sector) warns that the line is really one or two coins, not a sector trend. Layer 1 and Exchange tokens are most of the altcoin market itself, so they stay at the bottom of the heatmap as context; the rows are sorted by the 3-month change. A sector that the daily measurement has not covered yet says 'calculated, not yet measured'.

Every day the tool takes the 125 largest coins by market cap (or the 300 largest, when you switch to Top 300). The ranking is made first, before anything is removed. Then it removes Bitcoin and Ethereum, stablecoins, wrapped, staked and bridged copies of another coin, and tokenized real-world assets such as tokenized gold or treasury funds. Removed places are not refilled with coins ranked lower.

What is left is the altcoin market. The coins of a sector in it are the coins in the matching CoinGecko category. The share is the market cap of those coins divided by the market cap of the whole altcoin market, the sector included. Coins are matched by their CoinGecko ID, never by name or ticker. Top 300 makes small sectors such as DePIN or Privacy easier to see.

A day with no coins of a sector in the universe is a real 0%. A day with missing data has no number at all, instead of a made-up zero.

Market caps, ranks and the category lists come from the CoinGecko API. Each daily observation stores the 300 largest coins with their flags, so the same data can be recalculated later with a different universe size. A stored observation is never changed afterwards.

An observation is only stored when the full response passes checks: all 300 ranks present, valid market caps and recent prices. If a check fails, nothing is stored for that day and the page says so, instead of showing old data as new. A sector has measured days only from the day it was first tracked.

Daily measurement starts on 6 October 2026 (memecoins) and is stored per sector from the day it is tracked. To give the chart a past, the line before that date is calculated from past market caps. We take about 1,000 coins that are large today, look up their daily market cap since 2020, rank them for each past day, and apply the same exclusions and today's categories.

That is a good picture of the trend, but it is not recorded history. Top 300 can only be calculated from about 2023, when enough of today's coins existed.

Treat the number as a description of the market, not as something to trade on.

A made-up example. Suppose the memecoin share has moved from 9% to 5% over a year. That tells you memecoins became a smaller part of the altcoin market, not that they lost 45% of their value. A sensible next step is to look at the market cycle with the Cycle Map or the Altcoin Season Index before drawing conclusions.

Free members see every sector's current share in the heatmap, and follow two sectors of their choice in full: the last 12 months of their chart, their change over 1 week to 1 year and the coins they are made of. They choose each sector once; it cannot be changed later. Premium opens every sector, lets you overlay up to four, adds the Top 300 universe, the full history back to 2020, and the change over time and coin breakdown of every sector.