Do you know how a 'Mezzanine Certificate' functions?

We have to admit that even after 40 years working in the financial markets or with financial instruments we have only the haziest notion of how such an investment instrument is structured. So it is no wonder that a major financial institution is being sued by German investors who have been sold such a product. As always we advise investors to be vigilant and not buy investment products that they do not fully understand.