When you strip the noise away, the real question is simple: diversification is mostly a covariance problem, not a count-of-lines problem. Three quick checks before you act: 1. Name the mechanism in plain English: Owning more things does not automatically lower risk if the underlying drivers are still the same. 2. Say why it matters for behavior or portfolio decisions: Good portfolio construction asks what can hurt the book together, not how many rows exist in the holdings table. 3. Set the review question: Before sizing up, identify whether the edge comes from cash flow, volatility, timing or balance-sheet structure. Market translation: Ten software names can look diversified on paper and still act like one duration-sensitive trade. Failure mode: The usual mistake is measuring diversification by ticket count instead of by factor overlap. That is the kind of small conceptual habit that compounds into better decisions over time.