Over and Under Jitta Line is calculated following the principle of Upside Gain and Downside Risk, formula is as follow:
(Jitta Line - Price)*100 / Price
Examples
If Jitta Line = $10 and Market Price = $5
Upside gain = (10-5)/5 *100% = 100%
We refer this as "100% Under Jitta Line"
If Jitta Line = $10 and Market Price = $20
Downside risk = (10-20)/20 * 100 = -50%
We refer this as "50% Over Jitta Line"