margin deficiencyglossary / MARGIN DEFICIENCY margin deficiency. Securities. The extent to which the amount of the required margin exceeds the equity in a margin account. [Cases: Securities Regulation 45.11.] 词条贡献者 译员Roger,毕业于欧洲一流的高级翻译学院,专注翻译各种与公共及基础设施融资有关的法律文件。