Final answer:
During the Great Depression, the stock market lost $30 billion in value from September 1 to November 30, 1929, as it dropped from $64 billion to about $30 billion.
Step-by-step explanation:
During the Great Depression, in the span of approximately three weeks, the stock market experienced a significant loss of value. Between September 1 and November 30, 1929, the market's total valuation dropped from $64 billion to roughly $30 billion. This represents a $30 billion loss in that period, which reflects the financial devastation caused by the stock market crash. The crash didn't just impact the stock market but also affected the nation's banks and overall economy, leading to years of economic hardship.