The liquidity premium works in reverse
In financial theory, investors who accept illiquidity must be compensated for doing so. This compensation, the illiquidity premium, represents the additional return that private market investments offer over their liquid public market equivalents. It is not a reward for taking more risk. It is a reward for accepting a constraint that most investors either cannot or will not tolerate.
The data bears this out consistently. US private equity buyouts have outperformed the S&P 500 by 2.3% to 3.4% per year between 1986 and 2017, net of management fees, and this outperformance persists even when public equity indices are adjusted to reflect the nature of companies typically targeted by private equity. In private credit, the gap is equally clear. Put simply: the market pays you to be patient. And most investors decline that payment.
Why most investors stay liquid, and what it costs them
The preference for liquidity is understandable. Markets can be volatile. Circumstances change. The psychological comfort of knowing you can exit is real. But for most high-net-worth families and private clients, the actual need to liquidate a significant portion of the portfolio at short notice is far less common than the desire to maintain the option to do so.
There is a fundamental difference between needing liquidity and wanting the option of it. A portfolio structured around genuine liquidity needs, maintaining a liquid core sufficient to cover expenses, opportunities and unexpected events, can afford to allocate meaningfully to private markets without creating any practical constraint on the investor's life. The cost of maintaining excess liquidity beyond actual needs is the systematic forfeiture of the illiquidity premium, year after year, across every market cycle. Over a 20-year horizon, the compounding effect of this annual forfeiture is substantial.
Illiquidity as a behavioural advantage
Beyond the structural premium, illiquidity offers a second and less discussed advantage: it protects investors from themselves. Public markets are priced continuously. Every morning, the market tells you what your portfolio is worth, and on bad mornings, that number is lower than it was the day before. For most investors, this creates pressure to act. To sell when prices are falling. To reduce exposure when volatility is high. To time the market in ways that academic research has shown, repeatedly, to destroy value over time.
Private market investments have no daily price. Capital is committed for a defined period and cannot easily be withdrawn. This structure, which feels like a constraint, is actually a protection against the single most destructive behaviour in investing: the impulse to react to short-term market movements with long-term capital. A striking illustration came during 2022–2024, when a major non-traded real estate vehicle faced sustained redemption pressure as public REITs declined sharply. While publicly traded REITs declined nearly 10% over that period, the private vehicle, protected from forced selling by its illiquid structure, generated a positive total return of approximately 8%.
The three conditions required to capture the premium
The illiquidity premium is not automatic. Capturing it requires three conditions that must be met before committing capital.
Structure determines outcome
Most private portfolios are not structured to capture the illiquidity premium, not because the investor lacks sophistication, but because building the right structure requires intentional design. The difference between a portfolio that captures the premium and one that does not comes down to one architectural decision: whether the liquid core is sized to cover genuine needs, or sized to provide comfort.
The reframe
Liquidity is not inherently valuable. It is valuable in proportion to how much you actually need it. For investors who have structured their finances to cover genuine near-term requirements, excess liquidity is not prudence, it is the voluntary forfeiture of a structural return premium that the market offers to those patient enough to claim it.
The most sophisticated long-term investors in the world, university endowments, sovereign wealth funds, the largest family offices, understood this decades ago. Their portfolios reflect it. The question for every private investor is whether their own portfolio reflects it too.
The bottom line
Illiquidity, properly understood and deliberately chosen, is not a risk to be minimised. For investors who do not need the capital back within five years, it is a structural source of additional return, one that compounds quietly and consistently, precisely because most investors are unwilling to claim it. The market rewards patience. The question is whether your portfolio is built to be patient.
