The Lag: Why Private Marks Follow Public Markets by Two to Four Quarters

Every few quarters someone points out that private marks look detached from public markets and concludes that private valuations are fiction. The detachment is real. The conclusion is wrong.

What looks like denial is mostly mechanics.

Private assets reprice at events, not continuously

A listed share has a price every second because someone is willing to trade at it. A private holding has a price when something forces one: a financing round, a secondary sale, a quarterly valuation exercise.

Between those events the carrying value does not move, even when the underlying economics have moved a great deal. That alone produces a lag of one reporting period.

Then the negotiation adds another two

A round that prices in the second quarter was negotiated during the first, on comparables drawn from the fourth quarter of the previous year, using a data pack assembled before that.

By the time the round becomes a public data point it describes a market that has already moved. Stack that on the reporting lag and you reach two to four quarters routinely.

The same applies in reverse. When public markets recover, private marks stay low for a while, and managers who mark up early look aggressive rather than accurate.

The lag is symmetric, which is easy to forget

Commentary tends to notice the lag only on the way down, because a private book that has not yet marked down looks like a problem. On the way up it is just as real and rarely mentioned.

For anyone comparing a private portfolio against a public index, this matters: the comparison is only fair if both are measured at the same point in the cycle, which they almost never are.

Working with the lag rather than against it

Name it in the file. If your reference data is a quarter or two behind the market, write that down with the direction it biases in. An auditor who finds it themselves will treat it differently than one who reads your note.

Do not chase. Marking to the most recent public print each quarter imports volatility that the asset does not have, and reverses the following quarter.

Separate the two effects. When a holding moves, split the movement into market and company. The market part is the lag catching up; the company part is news.