Excerpt:Â The stock market peaked on Sept. 3, 1929. Two days later, financier Roger Babson gave a speech in which he warned, "sooner or later, a crash is coming, and it may be terrific." Later that same day, the market declined by 3 percent in what became known to history as "Babson's Break."
Banks issued margin calls to speculators using borrowed money to play the market. The Fed started tightening credit, squeezing investors further.