Setting buy and sell points for any investment security determines the investment’s final return. If the buy is made too early while the security is falling in price, the value investor loses out on not only additional margin upon the sale of that security, but also reduces their margin of safety associated with the intrinsic value point. It is similar on the other side of intrinsic value. If sold too soon, the value investor leaves money on the table. Thus, setting the buy and sell points are important decisions for every investment.
There are tools available to determine these two values. In the simplest of statements, the easiest rule to follow is the Pareto Principle, the old 80/20 rule. This rule basically states that roughly 80% of all outcomes are within 20% of of the value. With security pricing, this principle is simply that 80% of the value change will occur within 20% of the starting point. Thus, if a security’s intrinsic value is $80, then the probability is that 80% of the maximum change in value will happen within 20% points of the price shift. Therefore, the buy is approximately $64 and the sell point is $96. Almost certainly, this rule isn’t pure with security investing. The conception is that if the end results are beyond this 20 percent under and over the intrinsic value point, the value investor must have additional financial support and a lot of history with the security to validate expanding the buy and sell points beyond 20% fluctuation.
This lesson first introduces a basic model to illustrate and reinforce setting the respective buy and sell points. This model emphasizes an important aspect of price change. The angle of change affects the return on the investment. The steeper the price change, the shorter the time period for the change. The shorter the holding period for any investment, the greater the return on the investment. This is illustrated with a chart in this section of the lesson.