Seasonalysis uses a comparative analysis algorithm that goes through every year of available data to determine if any seasonal patterns exist. The minimum criteria for a valid seasonal pattern is at least 75% past repeatability. If you know that a good stock is going to dip lower than its 52 high. You can buy it on the cheap. One thing to know before you get started is that it does not come cheap. You have heard it takes money to make money. In this case that is a fact. Seasonalysis has a very high price. Seasonalysis is a unique app in that it does in fact work very well and is one of the few apps that can pay for itself in a matter of a few trades. There is nothing like it in the App Store and the closes program for the PC cost a few hundred more. The Pro Trader platform for the PC which has seasonal analysis by comparison cost $898.