It's safe to say that most engineers with a 401K and 20+ years experience gained and lost a lot more than $150K in a day several times in the last few years. This is extremely uninteresting.
The fluctuations on a 401K really are only significant if it occurs during a time in which you are relying on those funds, near or at or during retirement. Nobody with a 401K 'lost' anything in the last few years unless they withdrew from it.
Then I thought, "yup, another reason to avoid active trading, which I already know in my bones is a poor use of my time, money and energy" and stopped reading.