You’ve got to admire the staying power of the Dow Jones Industrials Average. It was replaced as the best measure of U.S. stock market performance in 1923, when Standard Statistics Co. unveiled its new stock index, which later became the S&P 500 (the Dow was and is simply the crude average of the prices of 30 subjectively chosen stocks). Within the investing business, both the Dow and the S&P have long since been supplanted by the more focused indexes compiled by the likes of Russell Investments and MSCI.