He presented himself as a financial expert, but he was nothing more than a fraud.

fraud 是名词，意思是"欺诈、欺骗行为"，也可以指"骗子"。这个词来自拉丁语fraus，本义就是"欺骗"。在金融领域特指通过虚假陈述或隐瞒事实来获取不当利益的行为。