A portfolio's SRI is not the average of its funds

What the SRI actually measures

Introduced by the European PRIIPs regulation (2017), the Synthetic Risk Indicator classifies financial products on a scale of 1 to 7 according to their market risk level. Unlike qualitative indicators, the SRI is a purely quantitative calculation: it derives directly from the annualized volatility of the product over a five-year reference period.

Each volatility band corresponds to an SRI level defined by regulation. There is no room for interpretation: once a product's volatility crosses a threshold, its SRI changes mechanically.

The direct consequence of this structure: a portfolio's SRI is calculated on the portfolio's volatility — not on the weighted average of the SRIs of its component funds. That is the crux of the matter.

The diversification effect on volatility

When combining several assets in a portfolio, the resulting volatility depends not only on each fund's volatility, but also on how they move together. This is what we call correlation.

Two funds that always rise and fall in the same direction (correlation close to 1) do not attenuate each other: the portfolio's volatility is close to their average. Conversely, two funds whose fluctuations are offset or opposed partially cancel each other out — which mechanically lowers overall volatility, and therefore the portfolio's SRI.

The more uncorrelated the assets, the more the portfolio's actual volatility diverges downward from the simple weighted average.

In practice, a portfolio balanced across geographies (Europe, North America, Asia), asset classes (equities, bonds, money market) and sectors exhibits average correlations between 0.1 and 0.4. At this level, the reduction in volatility versus the weighted average can easily reach 3 to 6 percentage points — enough to shift the SRI from one level to another.

Try it yourself: adjust the volatility, weights and correlation to observe the direct impact on your portfolio's SRI.

Implications for portfolio construction

Calibrating the target SRI upfront

A portfolio's SRI is not a secondary outcome observed after construction: it is a variable to be integrated from the allocation phase. The relevant question is not "what is the SRI of my funds?" but "what actual volatility will I obtain given the correlations between these assets?".

In practice, to target an SRI 3 (volatility between 5% and 12%), a typical allocation will include between 20% and 45% in equities, with the balance in bonds and fixed-income instruments. An SRI 4 (12%–20%) requires an equity allocation of around 55% to 75%. These ranges are indicative and depend heavily on the actual correlation level between selected assets.

Correlation as a lever

Two portfolios with identical equity allocations can display different SRIs if their internal correlations differ. A portfolio concentrated on a single geographic market will have stronger internal correlation than one diversified across several regions — and therefore higher volatility, all else being equal.

This is why geographic and sector diversification is not merely a prudential precaution: it is an active SRI management tool. Playing with correlations allows adjustment of a portfolio's SRI without necessarily changing asset class weightings.

The downward asymmetry

A frequently counter-intuitive point: it is much easier to lower a portfolio's SRI than to raise it. Diversification naturally operates downward. To reach an SRI 6, a portfolio would need volatility exceeding 30% over five years — which, with standard UCITS funds, is virtually inaccessible without resorting to highly concentrated strategies, illiquid assets or leverage.

SRI and consistency with client profile

The portfolio's SRI must remain consistent with the client's risk profile. This is a regulatory requirement, but also good construction practice: if the allocation shows an SRI 2 when the client has a dynamic profile, it signals that the composition is not aligned with their objectives — not necessarily a tool error.

What the SRI doesn't tell you

The SRI is a useful and standardized indicator, but it has its limits. It measures past risk over five years — a solid basis, but no guarantee of what will happen over the next five years. A fund that has been low-volatility in the past can very well go through a turbulent period.

It is also worth keeping in mind that the SRI captures "average" volatility — it says nothing about maximum possible losses, or about portfolio behaviour in the event of a sudden market crisis. Two funds with the same SRI can behave very differently during a sudden shock.

This is why the SRI is a starting point for qualifying portfolio risk, not a definitive verdict. It should be read alongside other indicators — maximum historical drawdown, recovery time after a decline, or adverse stress scenario analysis.