Secondaries are private markets' price discovery.

Between the day a fund buys a company and the day it exits, the position is “worth” whatever the latest mark says — a quarterly net asset value, produced by the manager, audited once a year. Public markets reprice a company continuously, in front of everyone. A private mark moves four times a year, smooths on the way up and on the way down, and in between, nobody is forced to test it against anyone willing to pay.

The secondary market is where the testing happens. When a limited partner's stake trades, a buyer who ran its own underwriting pays actual cash against the mark — sometimes at a discount, occasionally at a premium — and the gap between the two numbers is information. It compresses the asset's prospects, the credibility of the manager's marks, the seller's urgency, and the market's price for illiquid time into a single figure that someone was willing to wire.

Reading the spread

A single trade says less than it seems to — a deep discount may only mean the seller needed cash this quarter. The signal lives in aggregates and changes. When discounts widen across an entire vintage, the market is repricing an era. When one manager's funds consistently clear tighter than its peers', buyers are saying its marks can be believed. When a GP-led process prices an asset above its carrying value, the market is volunteering that the mark was conservative. Each of these is a statement no NAV can make about itself.

A mark is an opinion the manager writes down. A secondary trade is an opinion someone pays for.

As secondary volume grows, the signal thickens — more trades, more comparables, more of the private market with a shadow price attached. That cuts in both directions. Limited partners gain something closer to a market check on the portfolios they hold, and managers get told, in cash rather than commentary, how believable their marks are. Price discovery arrived late to private markets and came in through the side door: not a ticker, but a negotiated trade at a spread nobody publicizes. It is partial, lagging, and unevenly available. It is also a price — and the discipline is treating it like one.