[One picture to understand: History as a mirror, the US stock market has not been full of foam risks?] In the past year, the debate about whether the AI boom triggered the US stock market foam has been endless. However, according to the analysis of DataTrek's analyst team, since 1974, the S&P 500 index has often doubled - at least 100% - within three years before each foam peaked. This includes the Black Monday stock market crash in October 1987, the collapse of the Internet foam at the turn of the century, and even the peak of the COVID-19 bull market in January 2022. But currently, the increase in the index is far from reaching this standard.