An answer explanation from CFAI - only explicit costs such as the commission cost should be included in assessing the traders performance. Delay costs and missed trading opportunity costs are market movement costs and the trader should not be held accountable for them.
I don’t understand that at all because the texts discusses several other methods of measuring trading performance such as implementation shortfall (which includes explicit and implicit costs). I also can’t find anything specifically in the text that says only explicit costs such as commission costs should be included in assessing the traders performance.
Any insight?