Over the years I have tested many different ways and for me scaling out makes perfect sense be it scaling with profit but I also scale out of loss , nobody knows how far a market will go so taking bits off as it moves means you are paid and reducing risk all the time. Yes if you hold to full target you may earn more but the chances of this are low so at the end of the week the scales out give better returns every time for me.

There is a theory for longer term trades of scaling in to positions as the trend emerges , ie every pullback if stays above 200MA add a little more , building a position. Great for investment but not sure how good on interday trading