From about 1870 to the 1960s stock quotes were communicated using stock tickers that communicated over telegraph lines and printed thin strips of paper.

https://en.wikipedia.org/wiki/Ticker_tape

The system worked well until the 1960s when the volume of trading on busy days overwhelmed the system, sometimes delaying the quotes for hours. There had been plans to build a computer network already, but the data outages made it an urgent issue.

The classic book Business Adventures has a chapter on the chaos sowed by the failure of ticker tape.

https://www.amazon.com/Business-Adventures-Twelve-Classic-St...