Rebalancing a portfolio that is 40% illiquid: methods and data

A family office with 40% of its assets in private equity, real estate and other illiquid holdings cannot rebalance the way a pension fund with 40% in bonds does. UBS's Global Family Office Report 2026 puts the average office at 42% alternatives and shows private equity at 17% of the portfolio at the end of 2025, after a year in which respondents had planned a cut from 21% to 18%, as reported by Fortune. Outcomes and intentions rarely match in an illiquid asset class, in either direction. Rebalancing such a portfolio relies on tolerance ranges rather than fixed targets, on steering new cash flows rather than selling, and on the secondary market when neither is enough. The data show offices doing all three, slowly.

The denominator effect in practice

The problem has two halves. When listed markets fall, private holdings are marked with a lag and fall less, so the private share of the portfolio rises mechanically and the office finds itself above its range without having bought anything. When listed markets rise strongly, as they did through 2025 and 2026, the opposite happens and the private share falls, which can tempt an office into new commitments at the top. The second half is cash flow. Cambridge Associates' 2025 commentary records US private equity distributions of $185bn against contributions of $145bn, with the distribution yield below average for a fourth consecutive year, so the natural self liquidation that once brought private weights back towards target has slowed. An office that committed heavily in 2021 and 2022 can be above its private equity range for years with no action on its part, a situation examined in forecasting capital calls.

Method one: ranges rather than points

The standard response is to set a target with a band, for example 20% private equity with a range of 15% to 27%, and to act only at the edges. Wide bands on illiquid classes and narrow bands on liquid ones mean most rebalancing happens in the liquid sleeve. If private equity drifts to 26% because equities fell, the office does nothing to private equity and instead sells bonds to buy equities, restoring the liquid ratio while accepting the private overweight until distributions fix it. The data suggest this is how most offices behave. Citi's 2026 survey found more than 40% of respondents made no major portfolio changes during the year, and its 2025 report found 64% made no change to real estate and 50% none to fixed income. UBS's 2020 report, covering the pandemic drawdown, found 55% of offices rebalanced in March, April and May 2020 to keep long term allocations on track, an exception that shows how large a move is needed to trigger action.

Method two: cash flow rebalancing

The second method uses the flows the office cannot avoid. Distributions from private funds are directed to whichever liquid class is furthest below target rather than recycled into new commitments. Capital calls are funded from whichever class is furthest above. New commitments are sized against a model of future calls and distributions so that the private weight is expected to stay inside its range over the next three to five years rather than today. Goldman Sachs's 2025 survey found 34% of offices planning to reduce cash and redeploy into risk assets, and UBS's 2026 report found 65% of offices using leverage in some form, which includes credit lines used to bridge calls so that the office is not forced to sell equities at the wrong moment. The limitation is time: cash flow rebalancing moves a 42% alternatives weight by a point or two a year.

Method three: secondaries and financing

When the overweight is large or the family needs liquidity, the secondary market is the lever. Jefferies' July 2026 review records $118bn of secondary volume in the first half of 2026, up 15% on a year earlier, with LP portfolios pricing at about 87% of net asset value on average, 91% for buyout, 89% for credit, 79% for venture and 68% for real estate. Among LP sellers, 45% cited generating liquidity, 26% winding down older vehicles, 16% rebalancing over allocation concerns and 13% reducing non core strategies. Family offices were 5% of LP volume sold, so most offices are still using the first two methods. The mechanics of a sale are covered in how selling an LP interest works, and the alternative of borrowing against the portfolio rather than selling at a discount in secondary sale versus portfolio financing.

How often offices act

There is no survey that measures rebalancing frequency directly, and the indirect evidence points to infrequent, event driven action. UBS's 2026 report finds 60% of offices planning to change strategic asset allocation in the next 12 months, the highest it has recorded, and 86% keeping strategic asset allocation in house, yet the planned changes are a few points per asset class. Cambridge Associates' endowment data show the cost of drift: endowments with more than 40% in private investments earned a 10 year median of 9.3% against 7.6% for the whole group, but the three year median lagged a 70/30 benchmark by 300 basis points as listed markets ran ahead. An illiquid portfolio cannot be rebalanced precisely, so the policy should say in advance what the office will do at each edge of each range and which flows it will use, and the review should check whether the ranges were respected rather than whether the targets were hit.