Used for listed equity securities. Brokerage firm that is not a member of an organized exchange ( N.Y.S.E. ). Such firms execute their trades either through member firms, on regional exchanges where they are members, or in the third market.
NONMEMBER FIRM
Meaning of NONMEMBER FIRM in English
Campbell R. Harvey. Hypertextual finance English glossary. Английский словарь гипертекстовых финансов. 2012