This is simple indicator script for long term investors. It will check if the low of today is less than low of yesterday (or any time frame candle) and if the condition is satisfied, then the alert will be triggerred and that particular stock will be bought.
Each time a unit is bought, the average price is calculated and also the trget selling price, which is set at 100% above the average buying price. So once the price reaches that selling price target, the entire holding is sold.
The code resets all the variables back to 0 once a sell signal is triggerred.