What is a fund's vintage year?

A fund's vintage year is when it began investing (or held its final close, by some conventions) — the cohort label under which its performance is compared. Returns vary enormously by vintage because entry prices and exit environments differ across cycles.

Comparing a fund to its vintage peers, not to all funds, is the honest benchmark: a 2x from a bubble-entry vintage can beat a 3x from a cheap-entry one.