Hours after SEBI Chairman Tuhin Kanta Pandey warned CAS manipulators of strict consequences, the regulator released an Ex-Parte interim order pulling up two investment and brokerage firms, for allegedly manipulating in Closing Auction Session (CAS) in SENSEX on August 13 2026, the expiry day.

The Securities and Exchange Board of India (SEBI) charged Copthall Mauritius Investment Limited and Mansi Share and Stock Broking Private Limited with a fine of ₹3.7 crore as they allegedly manipulated the markets during the newly introduced closing auction session to determine closing price.

The alleged manipulation led to three spikes, and Copthall made large buy orders, constituting at least 85% of all buy orders made minutes before the SENSEX closed. Copthall simultaneously cancelled its latest buy order. SEBI determines a deviation from the average price to be at a maximum of 3% in the CAS. All of Copthall buy orders were above this mark.

Similarly, Mansi stock broking made large sell orders across eight SENSEX entities, constituting about 12.65 lakh shares. More than seven lakh shares were placed at a price of 2.5% below reference price and 4.6 lakh share below 1%. These sell orders were then cancelled in 4 to 5 seconds, the order noted.

“Copthall pushed the IEP of SENSEX higher by placing aggressive buy orders at +3%. They also contributed to 85% of the gross buy value….Mansi pushed the IEP of SENSEX lower for certain time period of ~4 to 5 minutes by placing sell orders at prices much lower than reference price and this downward pressure by Mansi was released when they cancelled their sell orders.. It is observed that the two participants adopted opposite but highly aggressive price-impacting strategies during the same CAS session,” said SEBI WTM Kamlesh Varshney in the order.

“These large buy orders and large sell orders which were placed and then cancelled, allowed Noticees to avoid losses or wrongfully profit themselves from positions in derivatives trades that otherwise would have expired worthless,” SEBI noted in its preliminary findings.

Mr. Varshney directed that Copthall and Mansi’s impounded about ₹3 crore and more than ₹71 lakh respectively. This applies to proprietary trading alone for Mansi. Both the entities are barred from trading in CAS in equity segment directly or indirectly. The bank accounts of the two noticees were to be frozen expect for the payment of penalty into the stipulated fixed deposit. SEBI also ordered that no debit shall be made in the demat accounts without its approval. Besides directing the noticees to provide an inventory of all assets, have been asked to cose any open positions, three months from the receipt of the order. The noticees are given 21 days to respond to the interim order.