As the main way to share in these capital gains was to purchase some ownership in those corporations, these individuals increasingly looked to invest their savings in the stock market. At about the same time, the informational problems that had constrained interest in common stock through the early 1900s were being reduced.
Rising demand from investors in the late 1800s for information about railroad companies had led to the proliferation of newsletters watching developments in that industry, and similar publications soon sprang up to provide information on other traded securities. These newsletters eventually evolved into ratings agencies covering a wide range of individual corporations, with Moody’s issuing the first bond ratings in 1909.