Wall Street closed its best month since 2023 with a quiet day of trading. The S&P 500 was essentially flat and edged down by less than 0.1% as it finished a winning week and its first winning month in the last four.

To this point, Buffett's consistent net selling activity since Oct. 1, 2022, has served as his big warning to Wall Street. It's called into question the stock market's historically pricey valuation, as well as reinforced something Berkshire's chief noted in his latest annual letter to shareholders: " Often, nothing looks compelling ."