You are right,a good business man must surely know that putting all investment in one business is as dangerous as putting snake under one pillow while sleeping.This is a saying that can serve as a good advice to persons with a stack of cash. The usual recourse is to deposit the money in the bank or to invest in stocks or bonds. Some others would invest in tangible assets like a car or motorbike that would be sold in the future for a profit.
When you save or you invest your money then be sure that it is somewhat scattered. Depositing all your money in one bank poses a risk. If the bank closes down then you can imagine the loss. Scatter your funds in at least 3 banks just to be sure. With investment never invest more than 10% of your liquidity in one scheme. Aside from the legit investments like government bonds and corporate stocks you can also engage in other investment but only in small amounts. In the course of time you never know what can happen to the economy. If you scatter your wealth then the potential loss will be minimal.