MARKET irrationality is a concept that is uniquely familiar to the stock market. For those who have been through market cycles over the years, I believe most would be able to vouch that the stock market is one crazy place. It is at times highly efficient but can be a complete mess.
On a long-term basis, it will make sense but the majority of investors are not long-term investors. This means if one gets caught up in the wrong cycle, they may very well lose everything. Conversely, if they are riding a tailwind of the market, they will land a windfall within a short span of time.