Greed – There’s an old saying that you may have heard regarding trading the markets, it goes something like this: “Bulls make money, bears make money, and pigs get slaughtered”. It basically means that if you are a greedy “pig” in the markets, you are almost certainly going to lose your money. Traders are greedy when they don’t take profits because they think a trade is going to go forever in their favor. Another thing that greedy traders do is add to a position simply because the market has moved in their favor, you can add to your trades if you do so for logical price action-based reasons, but doing so only because the market has moved in your favor a little bit, is usually an action born out of greed. Obviously, risking too much on a trade from the very start is a greedy thing to do too. The point here is that you need to be very careful of greed, because it can sneak up on you and quickly destroy your trading account.
The problem is that this is where traders are most likely to succumb to overconfidence bias. It's not uncommon for traders to complete a winning streak and then believe that they can't get anything wrong in the future. To believe this is of course unwise, and is only going to end in failure. Make sure you always analyse your trading sessions and look at your wins and losses in detail.