While this isn't a documentary it is quite an interesting watch. Indeed, some may call this an entertaining, strangely humorous clip. Basically this is coverage of the 1987 stock market crash by the Nightly Business Report. For those who weren't around then it gives a surreal insight into what people were thinking and feeling during the crash, and it rings similar tones to the crashes since then e.g. the Asian crisis, the dot com bubble, and the enormous volatility seen during the global financial crisis and just recently through the sovereign debt crisis.
First 10 minutes of the Nightly Business Report episode from Black Monday, October 19, 1987. The Dow Jones Average dropped by more than 22% that day to close at 1,738 with volume double the previous record (set the preceding Friday). Just two months earlier the average had peaked at 2,722, a level it would not see again for two years and would revisit for the final time in early 1991.
Finance Documentaries: http://www.financedocumentaries.com/2011/11/black-monday-nightly-business-report.html