Market sentiment flashes a warning signal, adding another worry for the bull market in US stocks.

The Zhitong Finance APP learned that the strong rebound in the US stock market may soon cool down, giving bulls in the stock market another reason to worry. The Bloomberg Intelligence Market Pulse Index reached the "frenzy" range last month, indicating that investor sentiment may have become overheated. This index combines six indicators such as market breadth, volatility, and leverage ratio to measure investor sentiment. When the index enters the overheated range, future returns in the next three months often weaken.