it is not the better way, it is the strictly sub-optimal way. If we bought 25% additional when 20% downfall happened, we would have received much more units than if we bought it if we averaged up. Another way to put it is, how far away from optimality are we ready to be, in order to stick to a quant system? That is a personal choice every investor has to make. It also depends on each investor’s investment goals. if the aim is to beat market returns by 4-5%, what you’re enumerating might very well work. But if the aim is to average 26% per year like samir vartak wants to (Great articles to read on the web - #1011 by harsh.beria93) then it definitely would not make sense, imho.