Listed companies will now have to answer the stock exchanges for any sudden spurt in their share prices or trading volumes and their replies would be made public for investors' knowledge.
In consultation with market regulator Sebi, the bourses have decided to enhance their surveillance measures with regard to any unusual movements in share prices and trading volumes of stocks, sources said.
So far, the two leading bourses -- NSE and BSE -- have been mostly making public clarifications received from listed companies about news reports containing price-sensitive information that were not intimated to the bourses and the regulator first.
However, the bourses would now make the clarifications public even if there are no news reports as such, as even unpublished rumours tend to create sudden fluctuations in share prices and trading volumes.
As is the case for clarifications on news reports, the bourses would post these replies on their websites for the benefit of investors.
While the bourses are automatically alerted in case of any sharp movement in share prices and trade volumes, they have mostly abstained from making the clarifications received from companies public, except in the case of news reports.
The move is aimed at putting a check on the practice of spreading price-sensitive information -- both in published or unpublished form -- by certain parties, which could be the companies themselves or even market operators, to manipulate share prices.
The BSE and NSE have already sought such clarifications from a couple of companies so far this month and would now enhance their vigil for any sudden spurt in share prices or trade volumes going forward.
Yesterday, both the BSE and NSE made public clarifications sought from Anant Raj Industries after the bourse observed a substantial increase in the stock's trading volumes in the recent past.
"The exchange, in order to ensure that investors have the latest relevant information about the company and to inform the market place so that the interest of the investors is safeguarded, had written to the company," the NSE said.
The BSE also said it has sought a clarification from the company and both bourses made the reply public.
In its reply, Anant Raj said that neither the company, nor any of its group entities or promoters, have any direct or indirect connection with the increased trade volumes.
The company, however, said that one of the reasons for the sudden spurt in trading volumes could be a "drastic fall" in the price of the company's shares in the last few sessions.
It further stated that the share price fall could possibly be due to news reports linking the company's name to the ongoing 2G telecom investigations, though it asserted that it had no direct or indirect interest in the telecom business.
Earlier, on February 16, the NSE had sought clarification from another company, Dhanus Technologies, on "significant price movement" in the company's stock.
In the reply made public by the NSE, Dhanus Technologies said: "There has been no specific announcement or information which would have an impact or bearing on the price or volume of the shares."
