The 10 largest U.S. companies accounted for 14% of the S&P 500 stock index a decade ago. Today, they account for more than a third. Tech euphoria has helped drive up the "Magnificent Seven" stocks: ...

Many investors accumulate concentrated stock positions through company stock options, inheritance or early investments in successful firms. While these holdings can create tremendous wealth, they also ...

Forbes contributors publish independent expert analyses and insights. I write about investing, markets and Berkshire Hathaway. Berkshire Hathaway’s (BRK/A, BRK/B) Warren Buffett and his late partner ...

One of the persistent themes in recent years has been the high and increasing concentration in US stocks. The outperformance of US stocks has been driven almost entirely by large cap US tech names and ...