Liquidity diversification is a dimension of portfolio construction concerned with the distribution of a portfolio’s holdings across different points on the liquidity spectrum — that is, how readily different assets within a portfolio can be converted into cash without a significant loss of value. It is often considered less prominently than diversification across asset classes or geographies, despite representing a distinct and, in certain circumstances, particularly consequential source of portfolio risk.
The concept of the liquidity spectrum
Financial assets vary considerably in how quickly and reliably they can be sold or converted to cash. At one end of the spectrum are highly liquid assets, such as cash itself or securities that trade in deep, active markets and can typically be sold quickly with minimal price impact. At the other end are illiquid assets, such as certain types of real estate, private equity, or other holdings that may take considerably longer to sell, or that may only be sellable at a discount to their assessed value if a sale is required quickly. A portfolio’s overall liquidity profile depends on how its holdings are distributed across this spectrum.
Why liquidity diversification is a distinct dimension
Portfolios holding assets at different points on the liquidity spectrum possess a genuine form of diversification that goes beyond return characteristics alone. Two assets might have similar expected returns and even similar correlation with one another under normal conditions, yet differ substantially in how easily they can be converted to cash if circumstances require it. This distinction becomes particularly significant during periods of market stress, when the ability to realise cash from a holding — rather than simply the expected return or volatility of that holding — can become the more pressing consideration for an investor.
Toby Watson’s perspective
Toby Watson, a finance professional whose career included nearly seventeen years at Goldman Sachs across structured finance, credit markets, and global principal funding before he joined Rampart Capital as a partner in 2020, has drawn specifically on his experience working across hard asset lending and structured credit to develop a detailed understanding of how liquidity characteristics affect portfolio behaviour, particularly during periods of market stress. For Watson, ensuring that the proportion of illiquid holdings within a portfolio does not exceed what an investor can genuinely afford to hold through difficult periods is regarded as a basic discipline of sound portfolio construction.
Key considerations in liquidity diversification
Among the practical dimensions of liquidity diversification that warrant attention are:
- The distribution of a portfolio’s assets across the liquidity spectrum, with an emphasis on ensuring that illiquid holdings remain within manageable proportions relative to an investor’s overall circumstances, rather than accumulating gradually to a point where they represent an outsized share of the portfolio.
- The mismatch risk between the liquidity profile of a portfolio and the potential cash needs of the investor holding it — a mismatch that can force asset sales at unfavourable prices if adequate liquidity is not available when it is needed.
Liquidity risk during periods of market stress
Liquidity considerations tend to become significantly more pressing during periods of market stress, when the ability to sell assets without an unfavourable price impact can become constrained across the market as a whole, not only for a specific holding. Assets that are readily convertible to cash under normal conditions may become considerably harder to sell at a reasonable price during a broad market downturn, meaning that a portfolio’s assumed liquidity profile, calculated under calmer conditions, may not hold during precisely the periods when liquidity is most needed. This dynamic parallels the way in which correlations between assets can also shift unfavourably during periods of stress, reinforcing the case for assessing a portfolio’s resilience under a range of conditions rather than assuming that its behaviour under normal circumstances will persist during a downturn.
Relationship to broader portfolio construction
Liquidity diversification is generally regarded as one component of a broader approach to portfolio construction that also includes diversification across asset classes, geographies, and underlying return-driving factors. A portfolio that is well diversified in terms of asset classes and factor exposure may nonetheless carry meaningful liquidity risk if a large proportion of its holdings cluster at the illiquid end of the spectrum, particularly if that concentration has developed gradually and without deliberate assessment. For this reason, liquidity is treated as a distinct discipline within portfolio construction, warranting its own periodic review alongside more conventional measures of diversification, rather than being assumed to follow automatically from diversification assessed along other dimensions.
