Macron fact checked Trump in public, a retaliation was expected. Honestly i am surprised it took that long.

If you want a reference there is a Rational Reminder Podcast (nerdy and factual personal finance podcast from a Canadian team) about this concept. It was the illustrated with trains or phone infrastructure 100 years ago : new technology looks nice -> people invest stupid amounts in a variety of projects-> some crash bring back stock valuations to reasonable level and at that point the technology is adopted and its infrastructure got subsidized by those who lost money on the stock market hot thing. Then a new hot thing emerge. The Internet got its cycle in 2000, maybe AI is the next one. Usually every few decade the top 10 in the s/p 500 changes.