In investing, any trade that has been established, or entered, that has yet to be closed with an opposing trade. An open position can exist following a buy (long) position, or a sell (short) position. In either case, the position will remain open until an opposing trade has taken place.

For example, an investor who owns 500 shares of a certain stock is said to have an open position in that stock. When the investor sells those 500 shares, the position will be closed.