If we are looking the age of 70-80 years, there won't be any more income flow, but rather, retirement benefits (if any). At this age, investment is no much a priority, cause age is far spent, and when it comes to investing in crypto currencies, Bitcoin is one and of which is best for the long term.

Also, such aged person, might not have the fluency is going through the market patterns on how to go around it, in terms of taking profits and buying at the deep.

The bottom line for this, should be for his/her children's benefits in life, cause for him, I don't think money is much important compared to family at this point. So, whatever he does related for money, is no more for him, but for his family.

IMO