We have had neither financial Armageddon nor a quick stock-market bounceback. For most clients, the answer is at least 10 years. It's an exercise in comfort.
Investors suffer from selective memory.
They remember that they thought about selling all their stocks on July 17. But they forget that they had that same thought 10 other times. By keeping a diary, they can see how often their hunches are wrong. You wouldn't want to move the whole lot, given where the stock market is right now. If you are underweighted in smaller U.S. stocks and foreign shares, both of which have been badly battered, consider building a full position.