A concerning amount of investor money in the market is riding on the wellbeing of a few big tech companies. And it got that way because the absurd valuations of those companies is built on speculation that AI will change the economy and company X will benefit from that for reason Y. When it becomes clear that either AI will not change the economy or that company X will not benefit greatly from said changes, that valuation will pop and investor assets will lose value. I'd call that a bubble