One of the four categories or quadrants of the BCG Growth-Share matrix developed by Boston Consulting Group in the 1970s to manage different business units within a company. A Dog is a business unit that has a small market share in a mature industry. It therefore neither generates the strong cash flow nor requires the hefty investment that a Cash Cow or Star unit would (two other categories in the BCG matrix). The term Dog may also refer to a stock that is a chronic underperformer and hence a drag on the performance of a portfolio.