Is the stock market in a bubble? What would make it pop?

I’ve been seeing the market climb to ever higher highs, even as everything else like gold is at an all time high. I’ve also seen people talk about the kind of earnings companies eventually need to justify the AI boom. It feels very bubbly but the market seems to be optimistic.

Is this a bubble? What sort of things might trigger it to pop - would disappointing earnings be enough or would it take larger events? It seems like in the short term demand for AI may keep revenues growing but does that mean the bubble may only be popped in a few years?