Patience is probably one of the hardest thing to learn for beginner traders. one of the most common mistakes in stock market trading is getting out or getting in too early. It takes years of experience to know and understand when it's the right time to get in order to get out. Most beginners have an itchy trigger finger, that is why patience is so critical to stock market success. Otherwise you could be jumping in and out of trades all too often because of volatility.
Getting in to early
Getting into early into a stock trade is common for beginners because they are anxious to make a quick buck. Without being in a trade you cannot make money. However, a common beginners mistake is to force a trade. If you do not see an opportunity, then do not force the trade - chances are you are forcing it and getting it to early. If you are early, things can change, stocks can reverse, or do the opposite of what you expect since they have not reached your entry trigger.
Getting out to early
Another common issue with beginners is getting out too early. Even if you got in at the appropriate time, most beginners sell quickly instead of letting their profits run as much as possible. They will pull the trigger to sell and get out making a measly $100 (in the stock market that's usually minor) if the stock goes up just a fraction or a tick from their entry price. In this case you are playing by ticks and just hoping and guessing. Don't do that!
Allow things to set up properly and ride the wave as much as possible. Know your trading strategy and your trading edge. Stick with it.