The Globe and Mail reports in its Tuesday, Aug. 6, edition that for the past couple of weeks, the share value of the S&P 500's bellwether tech stocks has been falling. The Globe's guest columnist Kean Birch writes that these include Alphabet, Apple, Amazon.com, Meta, Microsoft, Nvidia and Tesla. As these seven corporations now represent a big proportion of the U.S. stock market, any decline in value pushes down the overall public market, and this has been causing some panic. On Monday that panic evolved into pandemonium. Global markets tumbled, but Big Tech tumbled more. At one point, the AI standard-bearer Nvidia was down more than 7 per cent and the Magnificent Seven lost more than $500-billion (U.S.) in market capitalization. The question of why this is happening now is interesting: It looks like the generative AI bubble is finally bursting. Mr. Birch says investors are less and less confident that generative AI technologies will provide the necessary returns on the huge investments made. Hedge fund Elliott Management has stated that Nvidia is in an AI "bubble land" and that many AI technologies "are never going to actually work" or "will take up too much energy" -- undermining the hype around generative AI.