A vintage year groups funds by start date, not by return

The record

Alongside its pooled horizon index, Cambridge Associates reports a separate cut of the same underlying database: statistics grouped by vintage year. The firm's US Venture Capital Index and Selected Benchmark Statistics book, as retrieved on 16 September 2026, states the definition directly: "Vintage year is defined as the date of the fund's first cash flow, defined as the date of the fund's first LP contribution. Any investment activity taken prior to the first LP contribution is not taken into account." Every fund in the CA database is assigned to exactly one vintage year on that basis, regardless of when it eventually finishes investing or winds down.

What the sources establish

Grouping by vintage year is a different statistical cut from the calendar-period pooled index described in the same book. The pooled index answers what the whole eligible fund population returned over a trailing one, three, five, ten, or more years. A vintage-year cut instead answers what funds that started investing in a given year have returned since. The CA benchmarks FAQ states that vintage-year returns and aggregate returns by industry "are only reported once the sample size is sufficiently robust" to avoid identifying an individual fund, a confidentiality constraint rather than a comment on data quality. The CA benchmarks page separately notes that participating managers can request a fund's ranking "within their vintage year by IRR and Multiples," which only makes sense if the comparison set is peers that began investing in the same year.

Scope and revision

Because vintage-year assignment depends only on the date of first LP contribution, a fund's vintage year never changes, but the return reported for that vintage year does: as more capital is called and returned, and as unrealized holdings are marked, the reported IRR for that cohort moves with each new quarter of data, typically settling as the funds in the cohort mature. A five-year-old vintage and a fifteen-year-old vintage are not measuring the same thing even when both report a headline IRR, because the younger cohort still sits in the period where fees and unrealized markdowns dominate returns before exits arrive.

The decision in front of you

An investor comparing a fund's vintage-year IRR against a benchmark should confirm the benchmark cohort is drawn from the same vintage year, not simply the same asset class over some recent window; this is an editorial point that follows from the sources' own definition rather than an instruction CA states directly. Treating a young vintage's early IRR as directly comparable to a mature vintage's IRR risks penalizing a fund for being newer, not for underperforming.

• Is the benchmark IRR being compared drawn from funds of the same vintage year, or a different cohort?
• How much of the vintage cohort's committed capital has actually been called and distributed so far?
• Has the reported vintage-year return moved materially in recent quarters, and if so, why?

A vintage-year return is a snapshot of a cohort still in motion, and reading it as a finished number invites the wrong comparison.