Stock and bond prices are determined through trading, which means the buying or selling of an asset. To keep trading efficient, most deals in public assets are done through official marketplaces where everybody knows the rules and has the latest information. The NYSE and AMEX are actual physical places, located a few blocks away from each other in New York City. It has evolved into an organized securities market in its own right, and today is separate from the OTC market. Bond trading is similar.
Bond traders crave news.
They pay close attention to market indicators such as the indexes published by Lehman Brothers, Salomon Brothers and Merrill Lynch, as well as a range of statistics and news stories in the daily Bond Buyer newspaper and other publications. All this means that the professionals involved in capital markets are extremely well informed. In other words, you can't earn abnormal returns simply by reading more information about a stock. There are arguments for and against this theory. But the logic is sound.