If you had been too conservative for all 2018 you'd also have missed out on the few down days that eliminated all gains that year. So even if you sat out for a

If you had been too conservative for all 2018 you'd also have missed out on the few down days that eliminated all gains that year. So even if you sat out for a year due to your imprecise prediction, you'd have come out ahead of others who owned stocks. Problem is predicting which 8-12 month period the down days will happen. Seems like it should be reasonable to able to do that, but predictions of weather patterns over the same time range seem more accurate.