My uncle is not built for this

My father, who is currently indescribably happy about the development of his stock portfolio, wants me to help his younger brother as well. My uncle who is 72, has never taken a risk in his entire life, literally.

I will never risk my uncle's money on the stock exchange, he would not survive a bear market. Now I have to come up with a large number of excuses for not having time to help my uncle until we reach a bear market and my father's interest in helping his brother fallen. Tough times ahead.