Imagine valuing your real estate at exactly what you paid for it, and only updating that number the next time you sell. No appraisals, no comps, no updates. Nobody manages property that way, yet that’s exactly how most private company holdings are valued: a mark gets set at a funding round, then sits frozen for months or even years until the next one. Real estate developed appraisals and comps precisely because a purchase price goes stale the moment the deal closes; private holdings have never had an equivalent. For family offices holding direct stakes, secondaries, and LP positions, the Prime Unicorn Index is that missing comp sheet: an independent, current read on what a position is worth now, not what it was worth at the last round.
The Hardest Corner of the Portfolio to Price
Private companies have long been the hardest corner of the market to price, and the people who price them for a living know it. Apollo’s John Zito put it bluntly: “I literally think all the marks are wrong.” For family offices, the problem compounds, because private exposure rarely arrives through a single door. Direct stakes, secondary purchases, and LP commitments each carry their own vintage of stale mark, and all of them feed into the same reporting, planning, and allocation decisions. The exposure is real. The pricing usually isn’t.
Built From Documents Most Investors Never See
The Prime Unicorn Index family is a group of rules-based, modified market cap price return indexes tracking U.S. venture-backed companies valued at $1 billion or more: the Prime Unicorn™ Composite Index, with 234 components, and the Prime Unicorn™ 30 Index, home to names like SpaceX, Anthropic, OpenAI, Databricks, and Anduril. Every price change derives from publicly available, hard-to-source documents, paired with closed secondary transactions sourced through our partner, Caplight. Values are calculated daily, published weekly, and the index is reconstituted quarterly, a discipline it has maintained since launching in 2017 as the market’s first private company index. Every input is independently sourced, which means no self-reported marks and no guesswork.
A Benchmark That Works Like the Rest of the Portfolio
Family offices already hold their public sleeves to a daily standard; the Index puts the private sleeve on the same footing. It gives you an independent reference point for pricing the stakes already on the books, and a benchmark for measuring venture managers against something other than their own marks. It also delivers earlier visibility into up rounds, markdowns, and the IPO pipeline, all available on Bloomberg, Refinitiv, and Yahoo Finance. The results are visible in real time: on June 16, 2026, the Prime Unicorn™ 30 Index closed above 300 for the first time, a +203% climb from its base of 100 in January 2021, in the same week SpaceX priced the largest IPO in history at a $1.75 trillion valuation. Years of value creation behind closed doors, priced the whole way up.
Nobody would run a real estate portfolio off a purchase price from three years ago. An appraisal isn’t a formality; it’s discipline. For family offices, the Prime Unicorn Index brings that same discipline to the corner of the portfolio where the most value is being created, long before a ticker symbol ever exists.