Quote from NoDoji:
It's the part about holding the position that usually causes the trouble and it's especially troublesome if the trade is counter-trend.
Let's say for example, I expect ES to eventually pull back to 1088, I feel it may be nearing a turning point, and I decide to scale in 3 times if it runs against me with a disaster stop in place. So I short 1/3 @ 1105, 1/3 @ 1110 and 1/3 @ 1115, stop @ 1120. I'm now short a full position avg price 1110, with a 22 pt target and a 10 pt stop, decent R:R.
Price turns around after hitting 1117 and pulls back to 1107 where I'm finally green, then buyers step in and run it up to 1112, then price comes back down to the level where it was profitable and moves lower to 1102. So now the reversal is confirmed and the chance of my target being hit is far better than it was at any time during this trade. A seasoned professional sticks with his/her plan, but a lesser trader such as myself is in a position where I'm likely to take my profits early, before the 1088 target is reached, because I endured heat on the trade twice and now it's profitable and a profit's a profit's.
Allowing a full stop to remain in place but taking profits early skews the R:R and removes the profit cushion necessary for consistent profitability.
Now let's say I waited for a confirmed price reversal. Price dipped to 1107, tried to make a new high, failed and left a lower high, then came back to visit the first pullback low. I place my sell stop for a full position @ 1106.50, targeting 1088, and my stop is @ 1112.50 (just above the lower high). I have an 18 pt target and a 6 pt stop, good R:R, and same position size as my scale-in trade. It's now a lot easier for me psychologically to stay in the trade until full target is hit, because I entered on a breakout of a level, my stop is actually smaller and chances are better that I'll take much less heat on the trade because I'm trading in the direction of the new trend.
That's me personally, though. As I said a professional who's experienced with fading a move by scaling in as it runs against, would recognize the confirmation of a reversal and patiently wait for target to be reached.