LONDON — It is a truth universally acknowledged that transformative new technologies rewrite the rules of finance. Or so we are told in numerous commentaries, social-media posts, and regulatory filings relating to the current artificial intelligence (AI) investment boom, which may well prove to be a bubble. Fundamentals can be overlooked for only so long. For those too young to remember the dot-com crash of the early 2000s — which, I suppose, includes just about every AI industry leader right now — the late-1990s investment frenzy holds important lessons. The dot-com boom grew out of the early internet. Working as an engineer at the infrastructure level (designing the hardware and networks over which revolutionary new apps like Google, Napster, and Lastminute.com would run), I well remember the mood in the air. It was a frantic, explosive, inspiring roller-coaster, much like the AI boom, but without any talk of human extinction. One of the companies I worked for had an investor presentation with a picture of the Sierra Nevada mountain range. The text said: “In 1848, you didn’