Late last year I was in line behind two gentlemen who appeared to be in their mid-60's. One was boasting to the other that he just retired, and was putting his nest egg of $6,000 that week into buying Apple stock (at the time over $600 a share). He figured the rising value would take care of him for the future. I shuddered at the thought, because $6G is nothing to me but that's all he had. Less than six months later Apple dropped to $400 a share. Hope he didn't have a heart attack, losing a third of his life savings. Stock investing is gambling! For the young, not old geezers unless you diversify into different assets.
One day my old company’s stock price dropped from a high of about $68 to close one day around $10. That day a lot of people learned the wisdom of considering 401K investments outside of company stock.