The Global Risks Alliance (GRA)
Each institutional fund may be diversified on its own terms, yet many funds hold similar benchmarks, use the same consultants and managers, hedge with the same dealer banks and invest alongside one another in the same private deals. Those shared links can turn independent decisions into common behaviour under stress. This page sets out how cross-portfolio exposures form, how they can be measured from public records, and what the evidence serves for the investment committees and authorities who watch the system.
GRA · Established · service level R0
Institutional concentration is the similarity of behaviour and exposure across funds that each look diversified on their own terms. Many funds hold similar benchmarks, use the same consultants, managers and dealer banks and invest alongside one another, so they may act together in stress.
Where a portfolio's assets sit, and how much of its value is most exposed. Hypothetical assets, not an assessment.
The working screen behind this subject: its structure, terms and states. Names are placeholders and values illustrative.
Institutional concentration · Pension fund P · Valuation date Q3
| 1 | Cash and gilts | 477 | 0 |
| 2 | Index-linked | 567 | 1 |
| 3 | Credit | 422 | 5 |
| 4 | Illiquid | 693 | over 30 |
Cross-portfolio exposures. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Funds judged against peers or common indices converge on similar allocations, since deviating carries career and regulatory risk. When conditions change, they rebalance in the same direction at the same time.
A small group of consultants, asset managers, custodians and dealer banks serves many funds. Their advice, models and balance sheets become channels through which a single view or a single failure reaches many portfolios.
Funds hedging similar liabilities trade the same long-dated bonds and swaps. In a stress, simultaneous collateral calls force many sellers into a thin market, and the price fall feeds back into further calls.
Funds often hold large shares of their own government's debt and domestic assets, by rule or preference. This ties fund balance sheets to the sovereign and the domestic economy that also supports the sponsor and the members.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Herding | Investors making similar decisions at the same time, amplifying price moves. |
| Peer benchmarking | Judging a fund's performance against similar funds, which encourages similar allocations. |
| Home bias | Holding a larger share of domestic assets than global market weights imply. |
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Share of domestic government bonds held by pension funds | percent of amount outstanding | quarterly | Financial accounts and securities holdings statistics | OFFICIAL |
| Share of assets with the largest external managers | percent of externally managed assets | annual | Annual reports and manager disclosures | REPORTED |
| Holdings overlap between funds | cosine similarity, dimensionless | annual | Public holdings lists and regulatory filings | ESTIMATED |
| Allocation dispersion across peer funds | standard deviation of asset class weights, percentage points | annual | Survey and annual report data | ESTIMATED |
| Derivative counterparty concentration | percent of notional with the largest counterparties | quarterly | Fund disclosures and supervisory returns | REPORTED |
| Shared private market managers across funds | count of general partners held in common | annual | Annual reports and public commitment lists | ESTIMATED |
| Sector and regional concentration of holdings | Herfindahl-Hirschman index, dimensionless | quarterly | Holdings data | ESTIMATED |
The topic as a computational graph: named sources feed the methods, an evidence review gates the outputs, and the decisions stay with the authorities that hold them.
Fig. 02Nodes carry their type, two metric rows and a state; connectors show what feeds what; dashed frames name the owners; the timeline is the cadence. Design of the pipeline, not a record of a run.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| Federal Reserve Financial Accounts of the United States | Holdings of pension funds by instrument and sector, including government securities | Public domain |
| ECB securities holdings and pension fund statistics | Euro area pension fund holdings by issuer sector and country | Free reuse, attribution |
| Thinking Ahead Institute Global Pension Assets Study | Allocation trends and concentration of pension assets across markets | Free to read, registration |
| OECD Pension Markets in Focus | Asset allocation of funded pension arrangements across jurisdictions | Free reuse, attribution |
| SEC Form 13F data sets | Quarterly listed equity holdings of large US institutional managers | Public domain |
| Bank of England Financial Stability Reports | Analysis of crowding and feedback in liability-driven investment and gilt markets | Free to read, Bank of England terms |
| Holdings lists published by large public funds | Full or partial security-level holdings of sovereign and public pension funds | Public records, terms per fund |
Institutional Funds Nexus prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Investment committees and trustees | Whether mandates, managers and counterparties add up to more concentration than intended | Aggregated look-through exposure and counterparty concentration across mandates |
| Pension regulators and treasuries | Whether peer benchmarking rules or performance tests encourage herding | Allocation dispersion before and after rule changes; design of comparison benchmarks |
| Central banks and macroprudential authorities | Whether common exposures create a channel for forced selling | Holdings overlap, hedging concentration and stressed market depth |
| Legislatures | Whether domestic investment requirements or incentives concentrate fund exposure | Home bias and sovereign holdings evidence against diversification objectives |
The questions look across portfolios, not within them.
Common investment beliefs, benchmarks and regulatory incentives lead many funds to similar allocations. Index investing concentrates holdings in the largest listed companies. A small number of large managers and custodians serve a large share of the industry, creating operational dependencies.
When similar funds face the same shock, their responses, such as rebalancing, de-risking or raising cash, can be synchronized, amplifying market moves. Concentration is a property of the system, visible only by aggregating across funds, which is why it is suited to precompetitive, sector-level research.
| Method or data | What it shows | Limits |
|---|---|---|
| Aggregated holdings analysis | Common exposures across the sector | Depends on public or aggregated data; private holdings are opaque |
| Network analysis of service providers | Shared operational dependencies | Provider data may be incomplete |
| Behavioural and herding analysis | Synchronized responses to shocks | Hard to separate common signals from herding |
| System-wide stress testing | Propagation of shocks across funds | Requires assumptions about behaviour |
The current service level is R0: information and enquiries. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.