Methodology note
Combined denominators for related portfolios
A related-portfolio limit measures one exposure across several portfolios at once, such as a family's trusts, companies and personal accounts. The denominator is the combined value of every portfolio in scope, not each portfolio's own NAV. An issuer at 200 in one 500 account and 100 in another is 30% of the combined 1,000.
related_portfolio_concentration · Issuer concentration limit (single issuer, single instrument)concentrationWhy combine
Accounts are often governed separately, and some carry no limit at all, such as a founder's personal holding. Only a combined measure shows the family's total exposure to one company.
A clause such as across all family entities, no more than 10% in one company needs a combined measure.
How the registry measures it
The related-portfolio template measures the largest instrument, issuer group or counterparty group across every portfolio in scope. The denominator is the combined value of the set.
In the registry's worked cases, an issuer at 200 in a 500 account and 100 in another 500 account reads 30% of 1,000. That breaches a 25% cap; at 100 in each, it reads 20% and passes.
Pitfall: one gap stops the set
One unvalued holding in any member makes the whole set unmeasurable. A group limit read off part of the set is not a compliance statement.
Equally, a member without an accepted snapshot blocks the set-level number (AGGREGATE_MEMBER_NOT_ACCEPTED). Accept every member's data before relying on the combined figure.
Pitfall: who is in the set
Membership is a policy decision. Decide whether trusts with independent trustees, or a family foundation, belong in the set, and record why.
A set whose criteria match no portfolio measures nothing and reads not applicable (EMPTY_PORTFOLIO_SET). Acclimetry's Analysis view also rolls exposure up by entity or household, which helps check the set before the rule runs.
Worked example
Acme plc is 200,000 in the family trust and 100,000 in the holding company: 300,000 of the combined 1,000,000, or 30%, over a 25% cap. Every other issuer is within it.
Rule template:related_portfolio_concentration dimension: issuer
Bounds: hard max 25%
| Portfolio | Holding | Issuer | Class | Market value |
|---|---|---|---|---|
| Family trust | Acme plc | Acme plc | Equities | 200,000 |
| Family trust | UK Treasury 2030 | HM Treasury | Government bonds | 140,000 |
| Family trust | Global equity fund | Global equity fund | Equities | 160,000 |
| Holding company | Acme plc | Acme plc | Equities | 100,000 |
| Holding company | UK Treasury 2030 | HM Treasury | Government bonds | 100,000 |
| Holding company | Corporate bond fund | Corporate bond fund | Corporate bonds | 200,000 |
| Holding company | UK equity fund | UK equity fund | Equities | 100,000 |
| Group | Status | Value | Bounds | Headroom to the hard bound | Code |
|---|---|---|---|---|---|
| Acme plc | Breach | 30% | ≤ 25% | -5% | ABOVE_HARD_MAXIMUM |
| HM Treasury | Compliant | 24% | ≤ 25% | 1% | WITHIN_LIMITS |
| Global equity fund | Compliant | 16% | ≤ 25% | 9% | WITHIN_LIMITS |
| Corporate bond fund | Compliant | 20% | ≤ 25% | 5% | WITHIN_LIMITS |
| UK equity fund | Compliant | 10% | ≤ 25% | 15% | WITHIN_LIMITS |
ABOVE_HARD_MAXIMUM: The measured value exceeds the approved hard maximum, beyond any stated tolerance.WITHIN_LIMITS: The measured value sits inside every approved bound.
Largest contributors: Acme plc → Acme plc 20%, Acme plc 10% · HM Treasury → UK Treasury 2030 14%, UK Treasury 2030 10% · Global equity fund → Global equity fund 16%
Computed at build time by the Acclimetry rule engine (backend commit 8197063); the same code runs in the product.
Questions
Does a household cap add anything if every account has the same cap?
Not at the same percentage, because the combined weight cannot exceed the highest account weight. It matters when some accounts are uncapped or carry looser limits.
What is the denominator for a household?
The combined value of every portfolio in the set. An entity left out of the set drops out of both sides of the ratio.