SEBI Bars Two Entities From Call Auction Session

MUMBAI — The Securities and Exchange Board of India (SEBI) announced on Wednesday, August 19, 2026, that it has issued an ex-parte interim order prohibiting Copthall Mauritius Investment and Mansi Share and Stock Broking from participating in the call auction session (CAS) within the equity segment.

The regulatory crackdown follows a detailed market examination into suspicious trading activity during the Sensex Closing Auction Session on August 13, 2026. According to the regulator, the two entities deployed aggressive order placement strategies to distort indicative equilibrium prices in constituent stocks, allegedly seeking to benefit from expiry-day derivatives positions.

Investigating Closing Auction Session Manipulation

The inquiry centered on the newly introduced 20-minute closing auction session designed to improve price discovery across major index constituents. Investigators observed sharp index fluctuations driven by heavy order placement followed by substantial cancellations, prompting immediate regulatory intervention to preserve market integrity.

According to official regulatory filings, SEBI examination reports, and interim order disclosures:

• Trading Restrictions: Copthall Mauritius Investment and Mansi Share and Stock Broking are barred from participating in equity segment call auction sessions until further notice.

• Wrongful Gains Impounded: SEBI has ordered the impounding of approximately ₹3.67 crore in alleged wrongful gains identified from the entities' August 13 trading activity.

• Order Cancellations: Regulatory findings revealed large-scale order placements and subsequent cancellations across multiple index stocks designed to influence final settlement prices.

• Independent Actions: The regulator noted that while both entities engaged in disruptive trading patterns during the session, preliminary findings indicate they operated independently rather than acting in concert.

Official Sources Section

• Securities and Exchange Board of India (SEBI): Official interim orders, regulatory enforcement releases, and market surveillance updates.

• National Stock Exchange of India (NSE): Exchange compliance archives and member trading restrictions.

• BSE India Corporate Disclosures: Regulatory notices regarding market surveillance and trading member compliance.

Quote Section

According to statements released by regulatory authorities regarding the interim enforcement order:

"The regulator remains committed to safeguarding market integrity and protecting retail and institutional investors from abusive trading practices during sensitive settlement windows such as the closing auction session."

Why It Matters

For institutional investors, market participants, and regulatory analysts, strict enforcement action during closing auction sessions underscores SEBI's zero-tolerance policy toward market manipulation. Ensuring fair price discovery during derivatives expiry windows is vital for maintaining transparency and investor confidence across Indian capital markets.

Key Facts at a Glance

• Regulator: Securities and Exchange Board of India (SEBI).

• Entities Restricted: Copthall Mauritius Investment and Mansi Share and Stock Broking.

• Restriction: Prohibition from participating in equity segment call auction sessions.

• Impounded Amount: Approximately ₹3.67 crore in alleged wrongful gains.

FAQ Section

What action did SEBI take against Copthall Mauritius and Mansi Share and Stock Broking? SEBI prohibited both entities from participating in equity segment call auction sessions through an ex-parte interim order.

Why were these trading restrictions imposed? The regulatory action follows alleged manipulative trading and price distortion during the Sensex Closing Auction Session on August 13, 2026.

Did SEBI impound any funds from the entities? Yes, the regulator ordered the impounding of approximately ₹3.67 crore in alleged wrongful gains.

Where can stakeholders review official regulatory orders? Official enforcement orders and interim rulings are published directly on the Securities and Exchange Board of India portal.

Source: SEBI, The Economic Times, CNBC-TV18, Finimize