Global equity markets have experienced a remarkable upswing, with the MSCI World Index—a key indicator of stock performance in advanced economies—rising 33% to reach an all-time high. This surge follows US President Donald Trump’s decision on April 9 to pause “reciprocal” tariffs that had been proposed against many of America’s trading partners. While Trump’s fluctuating policy approach has contributed to positive market sentiment, the primary catalyst for this rally is the escalating hype surrounding generative artificial intelligence (AI).
In the United States, which carries a significant 72.4% weight in the MSCI World Index, the market capitalisation of the S&P 500 index has surged by an impressive US$21 trillion since the launch of ChatGPT, a widely-recognized AI chatbot, in November 2022. A noteworthy aspect of this rally is the concentration of gains among just a small number of companies. Specifically, ten firms are credited with accounting for over half of the increase in the value of US stocks. This concentration amplifies concerns regarding market stability, as the upward revision of earnings growth for the S&P 500 for the upcoming year is largely driven by this group of predominant technology firms, often referred to as the “Magnificent Seven.” In contrast, earnings expectations for the remaining 493 companies within the index have remained stagnant, indicating an “extreme degree of concentration,” according to Torsten Slok from Apollo Global Management.
Supporting this notion of concentrated power in the technology sector, a report from Societe Generale highlights that these top ten stocks represent one-third of the earnings for the S&P 500 and a fifth of the profits for the MSCI World Index. While such concentration may seem impressive, it poses significant risks, including the erosion of diversification in investment portfolios, thereby increasing exposure to the volatility of a narrow segment of the market.
The discourse surrounding AI is one of the most contentious in current financial circles, with numerous analysts and investors expressing skepticism about the sustainability of the AI-driven stock market boom. Many view the rapidly increasing valuations as indicative of a potentially unsustainable bubble. A recent Bank of America Global Fund Manager Survey underscored this sentiment, revealing that 33% of respondents identified an AI equity bubble as the most significant “tail risk” facing markets, a notable increase from 11% in the previous month. Additionally, an overweight position in the Magnificent Seven stocks has emerged as a favored strategy among traders.
While some investors acknowledge the possibility of a bubble fueled by the surge in AI investment—often characterized by soaring asset prices that become disconnected from realistic earnings potential—the market’s current trajectory continues to attract attention and speculation.


