Concept · Portfolio performance & risk decomposition
Active share
The fraction of a portfolio that differs from its benchmark; how much of the book is an active bet versus the index.
In depth
The fraction of a portfolio that differs from its benchmark. High active share + low tracking error is the signature of concentrated, low-correlation active bets.
In the methodology
How this compares to traditional risk models →Referenced by (2)
- Cascade Hedging and the Cost of Interpretability
Subsector ETF value, joint optimization, and executable hedge layers across 9,074 US mutual funds
- Who got NVDA right before it became benchmark exposure?
Early ownership, active conviction, and residual attribution in U.S. mutual-fund managers, 2019–2026