Sebi bans JP Morgan arm for manipulating Sensex closing auction

India's market regulator Sebi found that large institutions manipulated the new Closing Auction Session system, using substantial orders to turn losing trades profitable. Copthall Mauritius, a JP Morgan arm, was banned along with Mansi Share & Stock Broking. On August 13, Copthall placed orders worth over Rs 191 crore, comprising 87% of all trades in Sensex constituents, causing a 362-point spike within two seconds. Mansi Broking placed aggressive sell orders then cancelled them, amplifying a 405-point rise. Sebi ordered both to disgorge illegal gains of nearly Rs 3 crore and Rs 76 lakh respectively. The manipulation involved options contracts that would have expired worthless, with Copthall benefiting from Sensex movements and Mansi exiting put positions profitably. JP Morgan declined to comment on the matter.