When a trader can't pull the trigger to get into or out of a trade it is because
they don’t fully understand what it take to be a successful trader.  A trader is
gong to lose but he needs to win more than he loses and have the wins larger then
the losses.   The object is to have your net profit increase over time.

Some trading systems say the wins only have to take place 50% of the time.  In
this case they keep the losses small and winners large would have to be followed
closely.  Another type of trading system is that you would be profitable 65% of
the time and the losing trades would only be half the size of the wining trades.
The trader would have to take their losses and move on never moving the stop loss
unless it was to protect profit.  There should be a minimum draw down on the
trading account, this is like setting a stop-loss on the trading account as a whole.
When that level is hit all trading stops until the reasons for the losses is
determined and corrected or there is a change in the traders mental and emotional
view of the market.

Another way to look at it is when a trader will not enter a trade or cut his losses
is because of his ego and fear of being wrong. Also the lack of discipline in sticking
to his trading system will cause failure.  The trader may be trading money he can’t
afford to loose.  If there are exact entry and exit signals then he should stick to them.
Trading should be mechanical.  All the signals are their or the trade should not be taken.
The ego may over power the mechanical system because it wants to be better than any system.
Losses cause pain and pain hurts the ego so the trader doesn’t want to lose.  Loosing
happens to everyone and it is at this point the trader can have his career take off or
come to an end.  If the initial reasons for trading are strong enough to keep on trading
after a loss then there is a good chance the trader will be able to make it as a trader.