This is a guess based on anecdotes on recent volatile periods, the general scenario could be this: 1. Market falls sharply. 2. General public panic and sell,

This is a guess based on anecdotes on recent volatile periods, the general scenario could be this: 1. Market falls sharply. 2. General public panic and sell, while market timers double down. 3. Market falls further, market timers panic and sell. 4. Markets rebound sharply, with the above-mentioned people missing those good days. The key assumption is that at least some really good days usually follow really bad days.