Perpetual futures were invented to price things that don't trade. Perpetual futures were proposed in 1993 for housing, where there's no continuous market to quote against. @entropyIO's argument is that pre-IPO companies sit in exactly that gap. A private company has no listing date and no live spot price, so the contract treats the eventual IPO as the delivery event and prices in market cap rather than shares, which sidesteps the constantly shifting share count. That leaves the real problem: what does the oracle anchor to? Last-round marks lag, and an unanchored oracle gets pushed around on a thin book. Their answer is to let the market's own price count for more when there are real bids and offers sitting on both sides, and lean on outside references when there aren't. Moving right along the bottom means more real size resting on the book, and the curve shows how much of the price the market gets to set for itself. A thin book gets around a third of the say, a deep one closer to nine-tenths, and the line never quite reaches the top, so outside references always keep a small hold. Funding comes out of whatever gap is left, which means a deep book on both sides brings funding close to zero, while a book that empties out hands control back to the outside references.