ASML Drives European Stock Surge Amid AI-Fueled Concentration

New data shows that nearly 60 % of the Stoxx 600 index’s 8.8 % year‑to‑date rise is generated by just ten stocks, with the Dutch semiconductor group ASML alone contributing almost a quarter of the total gain. Analysts warn that this concentration creates a narrow return profile and short‑term vulnerability for European markets. The technology weight in the Stoxx 600 is about 8 % versus roughly 36 % in the U.S. S&P 500, but the AI wave has lifted semiconductor firms such as ASML, HSBC and others to dominate recent performance. “The return profile has become very narrow. It creates a clear short‑term vulnerability,” said Aneeka Gupta of WisdomTree, while Neil Birrell of Premier Miton noted that technology remains the big game as AI‑driven gains shift focus to European players.