I'm sure everyone here has a different strategy which works for them and you've already received good advice on developing an exit strategy before you buy or even when you buy. Most are from a trading viewpoint. I consider myself to be an investor, but I have previously held shares for a relatively short time period (less than a month). The reason for this is that my strategy to try and determine a fair price for a share. I buy when the price is significantly below the fair price and sell when the price is significantly above. During the period that I hold shares, I may have to revise the fair price I have calculated, but I usually sell all my shares when the go above my calculated exit price. You have to determine what level of risk you're comfortable with. If you're risk averse, you would probably sell all or most of your shares when they are at your exit price. If you're somwhere in between, you can lock in profits and hold on to the shares or pursue some strategy that involves selling part of your holding. If you're more risky or very optimistic about the share, then hold on to them for as long as you want.
