Mumbai: A day after the National Stock Exchange put a freeze on derivative contracts in 13 securities whose market-wide position limit had crossed 95 per cent, the country's leading bourse has asked investors to keep away from rumours and advertisements promising large returns.

NSE, which saw its benchmark Nifty index recorded the biggest single-day loss on Monday, asked investors to tread carefully before investing in equities.

NSE has asked investors to "do a thorough evaluation before trading in any security".

"Do not be attracted to stocks promoted by internet websites, research reports, tips etc unless you have done adequate study of the company," NSE said in an advertisement published in leading newspapers today.

NSE has asked investors to check information like price-volume data, financials and shareholding patterns before investing. The exchange also asked them to be cautious of stocks that show a sudden spurt in price or trading activity without a change in its fundamentals.

It asked investors not to be misled by rumours or inducements/advertisements that promise large returns.

The Bombay Stock Exchange benchmark 30-share Sensex also fell by 769 points on Monday - the second highest single-day fall in its over two decade history.

The Nifty witnessed a high level of volatility even today, swaying 164 points between its intra-day high and low levels.

The BSE Sensex recorded a swing of over 300 points in the intra-day trade today. It moved at least 20 times between the positive and negative territories during the day's trade.

NSE had banned additional derivative contracts in 13 securities whose market-wide position limit has crossed 95 per cent.

The exchange said in a notice, "Clients / members shall trade in the derivative contracts of these securities only to decrease their positions through offsetting positions".

The securities are: Adlabs Films, Alok Textiles, Bongaigaon Refinery, Essar Oil, Gitanjali Gems & Jewellery, Gmr Infrastructure, Hotel Leela, MRPL, Nagarjuna Fertilizers, Neyveli Lignite, Power Grid, Rajesh Exports, and Tata Teleservices Maharashtra.