It is shortened form for cabinet trade; a transaction/ trade in an inactive security (bond, stock, etc.) These securities are not traded often, and as such, there not very liquid and may not be trading at high price levels. The term “cabinet” was derived from the way such securities used to be tracked (in books in cabinets), where securities were classified as active, inactive, foreign and government. Inactive securities traded by means of cabinet trades were those remained in the cabinets more time than others, with orders remaining open for longer periods.