Think worst case is you don't make anything and you're then psychologically anchored to not get back into the market until your selling price is breached. I have a retired friend who sold his equities in 2012 at the all time high at the time, certain it was too high and a crash was imminent. In actuality, it never went lower than that point again and to this day hasn't bought back in missing out on massive gains these 8 years.