So, one difference between this and the dot-com bubble is that it is much, much harder to go public now, and much, much easier to raise funds as a private company. This has lead to loss-making private companies with valuations that would not have been remotely plausible a couple of decades ago. Arguably a more likely end to all of this is that the VCs turn off the tap, which will kill most companies in the space within a year or so, with fairly limited contagion to the broader markets; public companies who've gone heavily into it may be badly burned, but that would be about it.

Retail may never really get to participate at all, beyond trading Nvidia and similar.