Here's my theory about the dotcom bubble. The market correctly identified the internet as hugely valuable and correctly identified search engines as being able to capture a large share of this value. Consequently early search engines, chiefly Yahoo!, obtained (merited) high valuations. What Yahoo! did with their stock (they IPOd in 1996) was go on a big startup buying spree. This is what actually started the bubble: invest in some random dotcom crap company in the hopes that Yahoo! swoops in, buys and you get a big payday.

What caused the crash was Yahoo! being unable to do anything with their acquisitions and Google coming out with a better search engine, undermining Yahoo!'s core product. Google basically pulled the rug from under the dot com bubble.

The situation we're in now with LLMs is different, if I'm right we're actually pre-bubble, the bubble hasn't even started yet.