A recent interview on CNBC took place with a top quant from JP Morgan. This is what was said about the potential end of cycle period:

Sudden, severe stock sell-offs sparked by lightning-fast machines. Unprecedented actions by central banks to shore up asset prices. Social unrest not seen in the U.S. in half a century….

The forces that have transformed markets in the last decade, namely the rise of computerized trading and passive investing, are setting up conditions for potentially violent moves once the current bull market ends…

The current bull rally, the longest in modern history by some measures, has been characterized by extended periods of calm punctuated with spasms of selling known as flash crashes…

“If you have these liquidity-driven sharp sell-offs that come at the end of the cycle, or maybe even causes the end of the cycle, then I think you can have a much more significant asset price correction and even more significant increase in market volatility,”

… this potential meltdown in stock prices could cause the next financial crisis. His name for it: the Great Liquidity Crisis…

“Suddenly, every pension fund in the U.S. is severely underfunded, retail investors panic and sell, while individuals stop spending,” …

Blah blah…very insightful interview you should read about here

https://www.cnbc.com/2018/09/04/jpmorgan-says-next-crisis-will-feature-flash-crashes-and-social-unrest.html?__source=facebook%7Cmain

Market analysis for April 2 with severe down day includes Bitcoin