- Poor selection criteria; usually based on personal opinion, theory or tips and bad advice
They don’t stick to and commit to an approach; style drift
Don’t cut losses (#1 mistake made by virtually all investors)
Don’t know the truth about their trading – they fail to conduct in-depth post analysis
Treat trading as a hobby and not a business
Want too much too fast; learning a skill takes time

There’s a lot of important meat in those few lines of text. We all recognize that it’s not easy to cut losses, but I firmly believe that this results in more grief for traders than anything else. What causes a trader to suffer a big hit? I believe that it’s the unwilligness to accept that a trade is not working, and that it’s not likely to get any better if held longer. Under those conditions, losses mount. The only way to prevent that big loss is to cut it off at its knees – and the time to do that occurs when it’s a much smaller loss.The difficulty with that is sacrificing the possibility that the trade would turn profitable. My advice: Get over it. Many trades will be unprofitable. That’s a fact of life for a trader.
I understand that on a rare occasion a gap opening may do irreparable damage, and not provide an opportunity to take the small loss. However, that’s also a preventable occurrence. If the damage is too great, then the position was too large. It really is as simple as that.
How many of us look at trades after the position is closed? How many dissect the entire trade in an attempt to find out what was done correctly and what mistakes were made? Very few.
A mistake is not a trade that loses money. A mistake is making a decision that was clearly incorrect at the time, but the trader was unable to see that. Another mistake is avoiding a trading plan and not doing postmortems on your trades. It all takes so much time. However, if you take trading seriously, and do not consider it to be a hobby, there’s work to be done.
Mistakes are part of the game. Making the same mistake repeatedly is not. At least it’s not part of any successful trader’s game.