After the pair of each stock is identified, the trading rule is going to create a trading signal every time that the absolute distance between main asset and its pair is higher than d. The value of d is arbitrary, and it represents the filter for the creation of a trading signal. It can’t be very high, otherwise only a few trading signal are going to be created and it can’t be to low or the rule is going to be too flexible and it will result in too many trades and, consequently, high value of transaction costs. After a trading sign is created, the next step is to define the positions taken on the stocks. According to the pairs trading strategy, if the value of MA is higher (lower) than PA then a short (long) position is kept for MA and a long (short) position is made for the PA. Such position is kept until the absolute difference between the normalized prices is lower than defined threshold. Implementing such type of strategy is based on a logic that there is a good possibility that such prices are going to converge in the future, and this can be explored for profit purposes. If the distance is positive, then the value of MA probably will reduce in the future (short position for asset MA) and the value of PA is probably going to increase (long position for the PA). The same logic is true for the cases where the distance is negative.