Is smelting stone nonferrous metal a large-cap stock or a small-cap stock, ok?

According to the current situation in China, the stocks with circulation exceeding 1 100 million are generally large-cap stocks, and there are 255 million non-ferrous smelting stocks (available online) with a total market value of over 5 billion (also available), so they are considered as large-cap stocks. How can stocks be as simple as good or bad? Sometimes it goes up, sometimes it goes down. Isn't it just to seize the opportunity? (purely personal opinion. . . )