FRM Exam Part II · Illiquid Assets

Liquidity Risk and Liquidity Premium in Portfolios

Q: What is the liquidity premium on illiquid assets?

It is the extra expected return investors require for holding an asset that is hard to sell quickly at fair value. You estimate it as the return gap over a comparable liquid asset. It pays for lock-up, exit costs and the risk of being forced to sell.

Q: How do I adjust portfolio allocation for illiquidity?

First unsmooth returns to see true risk. Then test whether liquid holdings cover stressed cash needs such as capital calls and redemptions. Cap the illiquid weight so the investor is never forced to sell at a discount.

Q: How is liquidity risk different from market risk in private investments?

Market risk is the loss from price moves in risk factors. Liquidity risk is the cost or delay of exit, or the inability to fund obligations. In private investments, smoothed valuations also hide market risk until a sale or write-down.

Q: Is there a single formula for the illiquidity risk premium?

No. A common approach is the difference in expected return versus a comparable liquid asset. Another is required return minus risk-free rate minus the market risk premium. Read the question to see which one it wants.

Updated 11 October 2026 · Fact-checked

Liquidity risk is the chance you cannot trade an asset quickly at fair value. The liquidity premium is the extra expected return investors demand for bearing it. To solve questions, unsmooth returns, find the extra return over a liquid proxy, and adjust risk, allocation or discount rates for illiquidity.

Understand Liquidity Risk and Liquidity Premium in Portfolios

An asset is illiquid when selling it fast costs you a lot, or takes a long time, or both. Private equity, real estate, infrastructure and private credit are typical examples. You cannot exit at a screen price on demand.

Investors do not like this. So they ask for a higher expected return than a similar liquid asset would give. That extra return is the liquidity premium (or illiquidity risk premium). It pays you for waiting, for exit costs and for the risk of needing cash at a bad time.

Liquidity risk is different from market risk. Market risk is price movement from market factors. Liquidity risk is the cost or delay of turning the position into cash. The two are linked: in a crisis, prices fall and liquidity dries up together, and funding needs rise at the same moment.

Illiquid assets also hide risk. Appraisal-based valuations are smoothed, so reported volatility is too low and correlation with liquid markets looks too low. Reported Sharpe ratios look too good. You must unsmooth returns before you judge risk or set allocation.

For allocation, you need two checks. First, does the expected return after the premium justify the extra risk and lock-up? Second, can the investor meet cash calls and withdrawals without forced sales? A higher illiquid weight raises the chance of a liquidity squeeze, so limits are set from the investor's liquidity needs, not only from return.

Key formulas to remember

Liquidity premium: Liquidity premium = E(R illiquid) − E(R comparable liquid asset); Compare assets with similar cash-flow and credit risk. Otherwise you also capture other risk premiums.
Required return on illiquid asset: Required return = Risk-free rate + Market risk premium + Liquidity premium; Use this as the discount rate when valuing illiquid cash flows. A higher premium lowers present value.
Unsmoothing returns (Geltner, first-order): r(true,t) = [r(obs,t) − φ × r(obs,t−1)] ÷ (1 − φ); φ is the smoothing (autocorrelation) parameter, with 0 ≤ φ < 1. It is often estimated from first-order autocorrelation.
Volatility after unsmoothing: σ(true) ≈ σ(obs) × √[(1 + φ) ÷ (1 − φ)] ... approximately, for a first-order smoothing process; Unsmoothed volatility is higher than observed. Higher φ means a bigger correction.
Illiquidity-adjusted Sharpe ratio: Sharpe = (R − Rf) ÷ σ; Use unsmoothed σ. Using reported σ overstates the ratio.
Liquidity-adjusted VaR: LVaR = VaR + ½ × Position value × Bid-ask spread; Exogenous spread cost for liquidating a position. Useful for tradable but less liquid assets.

How to solve Liquidity Risk and Liquidity Premium in Portfolios questions

Use this order for most questions on illiquid assets, premiums and allocation.

1Identify the asset and the source of illiquidity: lock-up, thin market, appraisal pricing or funding constraints.
2Check whether reported returns are smoothed. If autocorrelation or φ is given, unsmooth before measuring risk.
3Recompute volatility, correlation and Sharpe ratio using unsmoothed data. Expect higher volatility and higher correlation.
4Estimate the liquidity premium as the return gap over a comparable liquid asset, or as the part of required return not explained by market risk.
5Use the required return (including the premium) as the discount rate, or compare the net-of-premium return with the liquid alternative.
6Check the investor's liquidity needs: cash calls, redemptions, margin and time horizon. Stress these in a downturn.
7Set or adjust the allocation so that liquid assets cover stressed needs. Reduce the illiquid weight if they do not.
8State the interpretation: what the premium pays for and what risk remains.

Quickest way: Three-check shortcut

When to use it: Use when time is short and the question gives a few numbers and four close options.

Smoothed data? If yes, true volatility is higher and the true Sharpe ratio is lower than reported. Eliminate options that say otherwise.
Premium? Subtract the liquid comparable's return from the illiquid one. Do this before any other work.
Valuation? A higher required premium means a higher discount rate, so a lower value. Then check the direction of your answer against that.

Common mistakes in Liquidity Risk and Liquidity Premium in Portfolios

Using reported volatility of private assets as true risk
Appraisal values are smoothed, so the numbers look calm and are easy to use.
Fix: Unsmooth first. Expect higher volatility, higher correlation with equities and a lower Sharpe ratio.
Treating the whole excess return as a liquidity premium
Students ignore other risk exposures such as equity beta, credit risk or leverage.
Fix: Compare with a liquid asset of similar risk, or remove the market risk component first.
Confusing liquidity risk with market risk
Both show up as losses in a crisis.
Fix: Market risk is price change. Liquidity risk is cost or delay of exit, or inability to meet funding needs. Name which one the question tests.
Applying the unsmoothing formula the wrong way round
The sign and the denominator (1 − φ) are easy to mix up.
Fix: Subtract φ times last period's observed return, then divide by (1 − φ). Check that the result is more volatile than the input.
Lowering the discount rate for illiquid assets
Students think a safer-looking, smooth asset deserves a lower rate.
Fix: Illiquidity adds to the required return. A bigger premium raises the discount rate and cuts value.
Ignoring investor liquidity needs in allocation
Focus stays on expected return and the premium.
Fix: Always test cash calls and redemptions in stress. The premium compensates only investors who can hold to maturity.

Worked examples

Example 1

A private real estate fund reports annual returns with volatility of 6% and first-order smoothing parameter φ = 0.5. Using the approximation σ(true) ≈ σ(obs) × √[(1 + φ) ÷ (1 − φ)], estimate the true volatility.

Show the solution

Compute (1 + φ) = 1.5 and (1 − φ) = 0.5.
Ratio = 1.5 ÷ 0.5 = 3.
Square root of 3 = 1.732.
True volatility ≈ 6% × 1.732 = 10.39%.

Answer: About 10.4%. The reported 6% understates risk, so the reported Sharpe ratio is too high.

Example 2

A liquid listed infrastructure portfolio has an expected return of 7.5%. A comparable unlisted infrastructure fund, with similar cash-flow and credit risk, has an expected return of 9.8%. The fund's expected cash flow in one year is $1,098,000, discounted at its expected return. Find the liquidity premium and the present value.

Show the solution

Liquidity premium = 9.8% − 7.5% = 2.3%.
Discount rate for the unlisted fund = 9.8%, so the factor is 1.098.
Present value = 1,098,000 ÷ 1.098.
1,098,000 ÷ 1.098 = 1,000,000.

Answer: Liquidity premium = 2.3%. Present value = $1,000,000. At the lower 7.5% rate the value would be higher, so the premium reduces value.

Exam tips

Questions often hide smoothing in a text clue such as appraisal-based or stale pricing. Treat that as a cue to unsmooth.
Expect direction-of-effect options. Know that unsmoothing raises volatility and correlation and lowers Sharpe.
Separate market risk, funding liquidity risk and market liquidity risk by name in your reasoning.
In allocation cases, check the investor's cash needs before looking at the premium.
Do not take the premium as guaranteed. It is expected compensation, not a realised return.

Practice questions from Illiquid Assets