"In the 1920s, Wall Street was a world that was really dominated by professional speculators and stock pools. These people had a monopoly over information"

The quote by Ron Chernow about Wall Street in the 1920s highlights a period in monetary history defined by an absence of openness and unequal access to market-moving information. Throughout this decade, the stock exchange ran in an environment starkly different from today's more regulated and information-rich setting. The phrase "controlled by expert speculators and stock swimming pools" underscores how certain groups wielded considerable impact over the marketplace.

Professional speculators in the 1920s were people or groups who traded stocks not based upon the fundamental values of the companies but rather on awaited market motions. They had substantial resources and gain access to, allowing them to control stock prices through large-volume trades. Stock pools, on the other hand, were groups of wealthy investors who conspired to increase stock rates synthetically. These pools would covertly collect stocks and then spread out positive rumors to bring in other investors, ultimately selling at peak costs for profit-- a practice that typically left ordinary investors with substantial losses.

The statement "These individuals had a monopoly over info" speaks volumes about the details asymmetry that existed during this period. Before the application of more stringent securities laws and the facility of regulatory bodies like the SEC (Securities and Exchange Commission) after the 1929 stock market crash, there were few barriers to avoid expert trading and other manipulative practices. Consequently, those with privileged access to financial news and company info might capitalize on their insights at the cost of less-informed investors.

Overall, Chernow's quote paints a photo of Wall Street in the 1920s as a play ground for the well-connected and wealthy, where market manipulation was rampant, and information was not democratically dispersed. This period eventually set the phase for future monetary reforms designed to cultivate greater market fairness and openness.