1792: Security traders meeting under a Buttonwood tree on Wall Street:

Early Stock Tickers:

The first stock ticker (top left) was invented by E. A. Calahan in 1867. Since then the ticker
underwent many changes. The advent of the ticker revolutionized the stock market by
making up-to-the-minute prices available to investors around the country. Previously,
updates from the New York Stock Exchange were carried by messenger or the postal
service.

Great Depression 1929: