Why the price on a private holding is not a market price
A last-round valuation is a historical fact about one negotiation, not a live quote.
When a figure appears next to a private company's name, it is worth knowing exactly what that number is — because it is not what the same number means next to a listed company.
What the figure usually is
Most commonly it is the price per share from the company's most recent primary funding round: the price one set of investors paid, on one date, under terms negotiated alongside it.
Those terms matter. Preferred shares in a funding round frequently carry liquidation preferences, anti-dilution protection and other rights that common shares do not. A price agreed for preferred stock is not automatically the value of common stock in the same company.
What it is not
It is not a live quote. Nobody is standing behind it. There is no continuous auction discovering it, no obligation on anyone to transact at it, and it does not update because sentiment moved.
How to read a change figure
A change shown against a private company is movement from that company's prior round to its latest one. It is a comparison of two negotiated events, sometimes years apart — not a market movement, and not a trend.
What that means in practice
Two parties agreeing a transfer price are doing original work. The reference figure is context for that negotiation, not the answer to it.