What does this even mean? That you invested the only money you ever invested entirely in the relatively brief period of the dot com peak? Who does that? (Obviously not nobody, but ...)
To all effects and purposes, nobody does that. So what it really means is "the money you invested during that one period (perhaps a year or so), and likely only the money you invested in dot com and adjacent stocks, has yet to be made back". In the meantime, the other money you invested before and after the dot com peak has done rather well, unless you specifically made some particularly disastrous choices.
That's pretty common for a mortgage
If you went all-in.. had no money in before and never invested after. Sure..
Great advice. So, ummmmm, how long is patient enough? 18 months, 3 months? What's low? Is this the lowest it's going to get? If you have answers to all of this, I want to invest in your fund.
The Boomers are using or investing that cash, though. Sooner or later anyway. And that cash would flow to the current owners of the things they are patronizing.
It's not like they're investing in dry ice and then throwing it in the ocean.
This notion of passive investing that has been pounded into peoples heads for years is complete bullshit and has only worked because there was always someone else ready to pay more for the same asset and because rates were perpetually held low. Some points to consider:
(1) You have fewer millennials than baby boomers, as the baby boomers cash out from their vanguard accounts, who makes up for the difference?
(2) If the S&P 500 contains companies built for a certain macro regime (low inflation, low interest rates), and the macro regime is shifting, you can be penalized by owning a set of assets that do not provide adequate returns (Tesla is currently the 5th largest weighting in the S&P, they don't pay you squat.)
Go look at charts of the S&P 500 beyond the last 40 years when rates were more variable, you'll see the market can at times be a shit investment vehicle that might not give you a return by the time you retire and on an inflation adjusted basis has a negative return!
Buy low, sell high. Save cash and be patient.