<prompt> Human: Since getting into investing in stocks I have been wondering when to sell a stock? As soon a stock value has increased a certain percentage or amount? E.g. if the value has increased by 10? Or should you hold onto it for as long as you do not need the money?  <response>: Two things:1 If you are investing, not trading, then you only sell a stock when the reason you bought it is no longer applicable. For example, if you bought Apple because you like that company and its products and you foresee growth in their future, the time to sell it is when it no longer seems to be growing as fast as before, and you are questioning its philosophies as a company. Otherwise, if you think it will continue to go up, you want to hold as long as possible in order to maximize your gains. Theres nothing wrong with selling smaller amounts of stock once you have kept them over a year so you only get short term capital gains tax to lock in gains.2 If you are trading, you need to sell on momentum. You should have a buying and exit strategy in mind whenever you look at a stock. For example, if you bought NVDA at 90, you should have had a plan to sell at 120. When it hit 120, you didnt have to sell, but you should have at least set a stop loss at 110 or 115 in order to guarantee gains. 