It’s likely some of these Americans might rethink pulling their money if they knew how quickly a portfolio can rebound from the bottom: The market took just 13 months to recover its losses after the most recent major sell-off in 2015. Even the Great Recession — a devastating downturn of historic proportions — posted a complete market recovery in just over five years. The S&P 500 then posted a compound annual growth rate of 16% from 2013 to 2017 (including dividends).
Stock market crashes are social phenomena where external economic events combine with crowd behavior and psychology in a positive feedback loop where selling by some market participants drives more market participants to sell. Generally speaking, crashes usually occur under the following conditions: a prolonged period of rising stock prices and excessive economic optimism, a market where P/E ratios (Price-Earning ratio) exceed long-term averages, and extensive use of margin debt and leverage by market participants. Other aspects such as wars, large-corporation hacks, changes in federal laws and regulations, and natural disasters of highly economically productive areas may also influence a significant decline in the stock market value of a wide range of stocks. All such stock drops may result in the rise of stock prices for corporations competing against the affected corporations.
Is Hoover to Blame for the Great Depression?
On October 24, many of the world's stock exchanges experienced the worst declines in their history, with drops of around 10% in most indices. In the US, the DJIA fell 3.6%, i.e. not as much as other markets. Instead, both the US dollar and Japanese yen soared against other major currencies, particularly the British pound and Canadian dollar, as world investors sought safe havens. Later that day, the deputy governor of the Bank of England, Charles Bean, suggested that "This is a once in a lifetime crisis, and possibly the largest financial crisis of its kind in human history."