That’s why investing a good portion of one’s portfolio in a diversified mix of quality equities long term as opposed to trying to time the market (in and out) as well as not having the portfolio dominated by just a few stocks is one of the best things one can do for their overall portfolio. A higher percentage in diversified equities is best at young ages with a gradual decline in the % as one approaches retirement. Also, increasing the percent in higher dividend stocks and reducing the percent in growth stocks is probably a good idea as one gets closer to retirement.