What is Market Cap?

Market capitalization is the current price of one share or token multiplied by the total number in existence. A company with 10 million shares at $40 has a $400 million market cap; a token worth $0.001 with 1 billion in supply has a $1,000,000 one. It's the honest way to compare sizes, because a low per-unit price means nothing on its own.

It's also routinely mistaken for the amount of money that has gone in, which it is not. Market cap is a multiplication using the price of the most recent trade. If the last trade of a thinly held token was for $200, every remaining unit is valued at that price on paper, and nobody had to put up the difference.

This is why 'but it's only $0.0001 per coin, imagine if it hits $1!' is usually nonsense — for that to happen, the market cap would have to exceed the GDP of several countries. Judge a token, or a stock, by market cap rather than sticker price, then ask how deep the order book is. The honest question isn't what it's worth on paper; it's what would happen to the price if someone actually tried to sell.