1722, porto folio; 1719 as port folio, from Italian portafoglio "a case for carrying loose papers," from porta, imperative of portare "to carry" (see port, n.1) + foglio "sheet, leaf," from Latin folium (see folio). Meaning "official documents of a state department" is from 1835. A minister without portfolio is one not in charge of a particular department. Meaning "collection of securities held" is from 1930; portfolio investment is from 1955.