The ticker's rise and fall

In the latest issue of Research magazine, I trace the history of ticker tape and the machines that ran it, a technology that changed the world. Excerpt:

From the 1860s to the 1960s, the stock market was a key source of financing for countless technologies and the industries that were built around them, ranging from railroads to airplanes to televisions to computers. But what made such financing possible, by enabling stock trading to occur with a speed, accuracy and scale never before seen in history, was the humble ticker tape.