Definitions
In plain terms
It helps estimate implementation activity when weights or members change.
Technical
The metric requires pre and post states at comparable prices, one-way or two-way convention, cash treatment, corporate-action normalization, rounding, and rebalance boundary.
Scope
Turnover is not transaction cost and providers can report different conventions.
Formula
Turnover_one_way = 0.5 * sum(abs(w_new - w_old))T=\frac{1}{2}\sum_i|w_i^{new}-w_i^{old}|| Symbol | Meaning | Unit |
|---|---|---|
w_new | post-rebalance constituent weight | decimal weight |
w_old | pre-rebalance comparable constituent weight | decimal weight |
Output unit: decimal portfolio weight
Examples
- A governed index record identifies index turnover with its applicable methodology version, effective time, source, and units.
Common misconceptions
- Index Turnover does not have one universal implementation without the named index methodology, data cutoff, and governance context.
Concept relationships
Prerequisites
Related
Required by
Where this concept is used
- ImportantCapped Free-Float Market-Cap IndexD03-F02-A04
- ImportantModified Market-Cap IndexD03-F02-A05
- ImportantEqual-Weight IndexD03-F02-A06
- ImportantIterative Cap RedistributionD03-F02-A07
- ImportantGroup-Level CappingD03-F02-A08
- ImportantIndex-of-IndicesD03-F05-A06
- ImportantReconstitution AlgorithmD03-F06-A05
- ImportantRebalancing AlgorithmD03-F06-A06
- PrimaryTurnover Buffer RuleD03-F06-A07
- ImportantIndex Replication-Cost EstimatorD03-F06-A08
Evidence and governance
- FTSE Russell Index Policy and Methodology Library FTSE Russell, London Stock Exchange Group · first party methodology
Supports: preferred label, short definition, technical definition, formula
Limits: The library links multiple documents with separate versions and applicability; the effective document must be identified.
- Fintech Builder Glossary Definition Contract The Fintech Builder · internal governed contract
Supports: variant distinction
Limits: Defines governed platform behavior rather than claiming these policies are universally prescribed by external McClellan methodology.
- Reviewed by
- fintech-builder-owner-approved
- Last reviewed
- 2026-07-27
- Next review
- 2027-07-27
- Record status
- published