The Securities and Exchange Board of India (SEBI) has slapped a massive ₹3.7 crore penalty on Copthall Mauritius Investment and Mansi Share and Stock Broking for manipulating the Closing Auction Session (CAS).

  • SEBI fined two firms a total of ₹3.7 crore for manipulating the SENSEX Closing Auction Session (CAS).
  • Copthall Mauritius used aggressive buy orders to artificially inflate the Index Equivalent Price (IEP).
  • Mansi Share and Stock Broking placed large sell orders to drive prices down before quickly cancelling them.
  • Both entities are now barred from participating in the CAS equity segment.

In a decisive move to safeguard market integrity, the Securities and Exchange Board of India (SEBI) has imposed a combined fine of ₹3.7 crore on Copthall Mauritius Investment Limited and Mansi Share and Stock Broking Private Limited. The regulator charged the firms with manipulating the newly introduced Closing Auction Session (CAS) in the SENSEX on August 13, 2026.

The enforcement action follows a stern warning from SEBI Chairman Tuhin Kanta Pandey regarding market manipulators. The investigation revealed that the entities exploited the CAS mechanism to influence closing prices, thereby securing unfair advantages in their derivative positions that might otherwise have expired worthless.

Read Also:From a Failed Class 12 Student to Leading a ₹300-Crore Company: Ashwini Kumar’s Remarkable Journey

The Mechanics of Manipulation

According to SEBI Whole Time Member (WTM) Kamlesh Varshney, the two participants employed aggressive, opposing strategies during the same session. Copthall Mauritius dominated the buying side, contributing to at least 85% of the gross buy value by placing aggressive buy orders at a +3% premium to the average price. Conversely, Mansi Share and Stock Broking exerted downward pressure by placing massive sell orders—totalling approximately 12.65 lakh shares—at prices significantly below the reference price, only to cancel them within seconds.

These large buy and sell orders, placed and then immediately cancelled, allowed the noticees to avoid losses or wrongfully profit from derivative trades.

BozokMedia analysis shows that such predatory trading patterns are specifically designed to exploit the volatility of the expiry day. By creating artificial spikes or dips in the IEP, these firms could manipulate the settlement prices of their existing derivative contracts.

Regulatory Implications and Penalties

The scale of the manipulation was significant; Copthall’s buy orders were consistently above the 3% deviation threshold allowed in the CAS. In response, SEBI has directed that approximately ₹3 crore from Copthall and over ₹71 lakh from Mansi be impounded. Furthermore, the regulator has frozen the bank accounts of both entities and prohibited any unauthorized debits from their demat accounts.

Did You Know?: The Closing Auction Session (CAS) was designed to provide a more stable and transparent price discovery mechanism at the end of the trading day.

Frequently Asked Questions

1. What was the primary method of manipulation used?
The firms used high-volume buy and sell orders to impact the Index Equivalent Price (IEP) and then cancelled those orders to avoid actual execution.

2. What are the immediate consequences for the firms?
They face heavy monetary penalties, account freezes, and a ban from trading in the CAS equity segment.