If the trading costs are a small fraction of the total trade amount in AIM, or in any other Trading Management system, then it will make little difference for the Next Trade Amount Advice. The same can be said for rounding up or down the Trade Advice to avoid fractional share acquisitions.
If one is rounding up & down to round numbers of 100 shares it will affect the next Trade Amount but that is also irrelevant: one can arbitrarily decide to trade less than the system advices. . .In fact AIM does that by definition with setting the SAFE value to an arbitrary value. Another arbitrary alteration is the Hold Zone setting: each one of these affect the trading actions, often knowing that these settings may not be optimum, but ignoring a cost factor as part of the equity price creates inaccurate yield calculations that should be avoided.
If the trading cost are relatively high and if they are not accounted for as investment then the investor does not have an accurate indication of the performance of the investment. Suppose an investor is not sure if an investment is safe and he hires a consultant that cost $ 2000 per year. No matter how you look at it, that money IS an investment of $ 2000/year in that equity and not including it in the investment calculations distorts the Investment Yield. If people do not mind that then it is no problem. A good management system should account for and incorporate investment costs in a specific way so that it figures correctly in the yield calculations & the Next Trading Calculations.
If one pays a lotof money for buying equity and does not consider these cost as an investment then it seriously affects the Yield Calculation in a negative way. There is no escape from that conclusion.
