Mean Reversion : Received inquiry from friends / readers about "plotting regression line " for major stock markets other than STI . Would like to reiterate here that the " regression line " is just a "statistical phenomena " same as other indicators in Technical Analysis where we are just using past price trend or movement to manipulate or so call " forecasting " the future price movement . Whereas "mean reverting " is just a situation that showing market move in "cycles " and tend to revert to mean if there is any "over-shooting " in both directions ( where everyone is either too optimistic or pessimistic ) . Concept Explained : by Investopedia  What is the 'Mean Reversion' Mean reversion is the theory suggesting that prices and returns eventually move back toward the mean or average. This mean or average can be the historical average of the price or return, or another relevant average such as the growth in the economy or the average return of an industry ......