Market capitalization affects ASX stock grouping by categorizing listed companies based on their overall market size. It is calculated by multiplying a company’s total shares outstanding by its current market value per share. On the ASX, companies are commonly grouped into large-cap, mid-cap, and small-cap segments. Large-cap stocks usually represent established businesses with higher market presence, while mid-cap and small-cap stocks reflect comparatively smaller enterprises. These groupings help organize the exchange, support index composition, and allow easier comparison among companies with similar market sizes, improving clarity when reviewing ASX stock listings and performance data.