Axes and quadrants
The BCG matrix is a framework for discussing a portfolio of business areas along two axes: the growth rate of the selected market and the area’s relative market share. It is not a matrix of securities returns. A large share in a growing market is called a “star”; a large share in a slow market is a “cash cow”; a small share corresponds to a “question mark” when growth is high and a “dog” when growth is low.
For example, a business area with a small share of a fast-growing market falls into the question-mark area. This is a reason to examine investment needs and the possibility of strengthening the position, not an instruction to invest immediately. Define the market boundaries, growth period and rule for comparing shares in advance.
Limits of the framework
The trap is to treat a quadrant name as proof of future cash flow. A strong share does not guarantee a durable advantage, and relationships between business units and mandatory investment do not fit on two axes. Supplement the matrix with analysis of the business model, risk and return on capital, while retaining the option to reject the proposed classification. Related reading: [business model](/guides/business-model-drivers/).
Sources and review boundaries
Support: **gl-bcg-matrix**, **gl-bcg-classics**. The BCG page and the authors’ 2014 article were checked against their full texts. The historical method is not a market forecast or a recommendation to allocate real investments.