The concentration of gains in the US stock market has reached a 35-year high, and analysts warn that the market may take a breather

According to Jinshi reports, driven by optimistic sentiment towards AI and strong earnings reports, both the S&P 500 index and the Nasdaq have reached all-time highs. However, this round of increase clearly lacks breadth, with most of the gains primarily contributed by large tech stocks. UBS analysts pointed out that in the six weeks ending May 15, the lead of the market-cap weighted S&P 500 index over the equal-weighted S&P 500 index reached the largest margin in at least 35 years. UBS recommends that investors reduce overly concentrated positions and guard against concentration risk.