The best way to look at any business is from the standpoint of the clients. So there are these certain basic things that aren't going to change. Companies are going to have needs for equity, debt, advice, FX, and derivatives. Individuals are going to have needs for auto loans, mortgages, something that looks like a deposit account, and the ability to send money to people. Those things aren't going to change.
Have you ever been bitten by an elephant? How about a mosquito? It's the little things in life that will bite you. For most of us, it's the frequent, small and seemingly inconsequential choices that are of grave concern.