While technically occurring over a few days ("Black Thursday" and "Black Tuesday"), this crash was a swift turning point that initiated the Great Depression, characterized by a rapid loss of confidence and massive sell-offs. Key Themes in Fast Crashes:

Modern crashes often feature computer-driven trading, which can trigger massive, instantaneous sell orders.

Unexpected, major negative news (like pandemic shutdowns) causes rapid reassessment of asset values. Helpful Resources & Context:

This was the fastest drop from a market high to a bear market (a 20% decline) in history, occurring in just 16 trading days [1]. It was driven by panic over the global pandemic.

has an in-depth, detailed explanation of Black Monday (1987) and its causes.