A discretionary stock-picker and a quant systematist can sit in the same office, target the same benchmark, and run portfolios that share almost no DNA. The exam tests whether you can place each strategy on the right map.
Fundamental active investing is judgment-driven. The analyst builds a thesis on a small set of names, models earnings, talks to management, and concentrates capital where conviction is highest. Quantitative active investing is rule-driven. The portfolio manager defines signals, tests them on history, and applies them across hundreds or thousands of names where each individual edge is tiny but the breadth produces a meaningful information ratio.
KEY: The Fundamental Law of Active Management ties the two together. Think of active return as skill per bet times the number of independent bets, scaled down by how cleanly you can implement the signal in a real book. Each lever compounds, so doubling skill or quadrupling breadth has the same effect on the ratio.
. Fundamentals push IC (skill per bet); quants push BR (number of independent bets). Both can win, by different routes.
Common mistakes
- Calling any concentrated book "fundamental." Concentration is a portfolio-construction choice, not a research style. A quant can run 20 names; a fundamental manager can run 200. Trap: classifying by position count instead of decision process.
- Treating top-down and bottom-up as mutually exclusive. Most real strategies blend. Trap: forcing a "thematic growth" fund into one bucket on the exam.
- Ignoring transfer coefficient. Constraints (long-only, sector caps, turnover budgets) cut the realized IR by 15-40%. Trap: quoting the unconstrained IR as the deliverable.
Bottom line
- Fundamental managers think in narratives, hold concentrated books, and accept high active risk; quants think in distributions, hold breadth, and exploit small edges across many names.
- Bottom-up starts with the company, top-down with the macro regime, factor-based with persistent drivers (value, momentum, quality, size, low-vol, profitability).
- Both approaches fit IR = IC × √BR × TC, where the transfer coefficient (TC) captures how constraints erode the realized information ratio.
- Factor premia are not stationary; crowding and decay are their main risks, so tilts should not be sized as if Sharpe ratios are constant.
Exam shortcut
When the vignette describes a process, tag the dominant decision driver (company, macro, factor, governance, statistical signal) before classifying. That single tag resolves most style questions. For activist questions, remember the 5%/10-day Schedule 13D trigger. It shows up in case after case. For fundamental law questions, never quote the unconstrained IR. Multiply by TC (typically 0.7 to 0.9), then compare to fees plus a hurdle before judging viability.
The full lesson (about 2,382 words, 16 min read) adds 2 worked examples, all 6 common mistakes, a self-check, free in the app.
Learning objectives
- active equity strategies
- active equity construction
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