"Only liars manage to always be out during bad times and in during good times." - Bernard Baruch 10 days . That's all you need to miss for your investments to be cut in half. Markets are wildly unpredictable. They can swing 15% in either direction on any given day . Market timers try to be invested in the good days and be absent for the bad days ( like a terrible friend ). This strategy sounds simple enough but is practically impossible to implement. Why? Because no one can predict the future. Timing the market is hard but mistiming the market is easy. There's only a handful of great market days and they drive the majority of returns. Not being invested on these days severely handicaps your performance. J.P Morgan's 2019 Guide to Retirement analyzed the 20-year return of the S&P 500 from Jan 4 1999 - Dec 31 2018. Annualized returns were 5.62% . If an investor invested $10K and had the discipline to not tinker with their investments, their portfo...