For many years I worked in the investment department of a major bank. Even though our services were offered through the bank, the non banking financial services we provided were different than the bank services.
When someone deposits money in bank products, you know how much interest you will be receiving, and the principle amount of money you invest will not decrease.
Banking products are also regulated by the FDIC. The financial products and services we provided were regulated by the SIPC and NASD.
We sold stocks, bonds, mutual funds and annuities, which are not the same as CD's or money market accounts.
When someone invested money in the financial services we provided, they had to know the risks that were involved. Because of the nature of these products, they could end up having less money depending on what the market did.