Morningstar separates stock portfolio holdings into five market-capitalization groups:
Giant
Large
Medium
Small
Micro
Rather than using a fixed number of “large cap” or “small cap” stocks, Morningstar uses a flexible system that isn’t adversely affected by overall movements in the market. World equity markets are first divided into seven style zones:
United States
Latin America
Canada
Europe
Japan
Asia ex-Japan
Australia/New Zealand
The stocks in each style zone are further subdivided into size groups. Giant-cap stocks are defined as those that account for the top 40% of the capitalization of each style zone; large-cap stocks represent the next 30%; mid-cap stocks represent the next 20%; small-cap stocks represent the next 7% and micro-cap stocks represent the smallest 3%. For value-growth scoring, giant-cap stocks are included with the large-cap group for that style zone, and micro-caps are scored against the small-cap group for that style zone.