I'll believe it the day SpaceX - the AI company that is mostly making money selling datacenter compute using gas turbines for energy - takes a single day 90% or greater drop in stock price.
Be careful what you wish for. The repercussions might be titanical.
Currently nobody knows when the first big financial crisis is fully locked in. For example, if OpenAI can't close another round, and they default on their contracts with Oracle, there's your sign. Until then it looks like everybody is enjoying the communal hallucination.