Megacap U.S. stocks are carrying the rest of the world. Here are the risks, and where to look for diversification

Megacap tech stocks aren’t just powering the U.S. stock market — they’re also holding the world together. U.S. equities now comprise 70% of the MSCI World Index, the benchmark for large- and mid-cap companies across 23 developed markets. This level represents the largest country weight since the index’s inception in 1986; and correspondingly, the lowest exposure to non-U.S. stocks. The top five largest-cap U.S. stocks — Apple , Microsoft , Nvidia , Amazon and Meta — account for nearly a fifth of the index. The MSCI World Index shifts regional and country weights based on broader economic trends. Japanese equities…