Neuberger Berman Warns AI Stock Concentration Raises Risk as Yields Rise

Neuberger Berman President and Chief Investment Officer for Equities Joe Amato warned that U.S. stock portfolios may carry outsized artificial intelligence risk as rising Treasury yields complicate diversification.

Neuberger Berman estimated on Oct. 5 that AI-related companies represented 25% to 28% of U.S. stock market value but about 50% of marginal risk. That gap led Amato to urge investors to examine how much of their portfolios depends on the same theme.

The concern extends to bonds. Amato said a resilient economy, technology-led growth and AI infrastructure investment have helped lift both equity markets and Treasury yields. Even high-grade bonds may be exposed to those shared forces, potentially reducing their effectiveness as a counterweight to stocks.

Amato’s fourth-quarter outlook remained broadly constructive on risk assets, though he adopted a more cautious stance for the near term.