I think the reason for the drop is the reaction to 3% oversubscription ,that shows demand for the share which was discounted was not that impressive .....I think once the shares begin trading on 21st there could be some drop on the share price.
'......to the acknowledgment of the mystery of God, and of the Father, and of Christ; 3 In whom are hid all the treasures of wisdom and knowledge.' Colossians 2:2-3