Contrast discretionary fundamental management with quantitative active management

Fundamental managers rely on in-depth research and judgement about individual companies, forming a forward-looking view of each firm's value; portfolios tend to be concentrated and each holding has a clear thesis. Quantitative managers build rules from data, ranking many stocks on factors such as value, momentum and quality, then optimise broadly diversified portfolios with a risk model. Fundamental work is subjective and depth-oriented, with risk judged position by position; quant work is systematic and breadth-oriented, with risk controlled at portfolio level. The trap is thinking the two never overlap: quants use economic reasoning to choose factors, and fundamental managers screen with quantitative tools. Their typical weaknesses differ too: behavioural bias for fundamental managers, model risk and data-mining for quants.