Perspectives from ISB

Price manipulation and role of unscrupulous brokers in capital markets has historically been a subject of great concern to market participants and Governments since it has an important impact on market efficiency. Price manipulation can occur in many ways, from false information to accounting and earnings alteration to stock price manipulation or what Allen and Gale term “Trade-based manipulation.”

Allen and Gale (1992) confirmed that it is possible for an uninformed speculator to make profits from ‘trade-based manipulation’ with large traders frequently buying and then selling substantial blocks of stock.


Anecdotal evidence from the Indian capital markets suggest that many such price manipulation strategies exist reducing the market efficiency, and also indicate the existence of front-running by traders primarily before large trades. The fact that SEBI has sent more than 500 show-cause notices in the past four years to various brokers, financial institutions and traders regarding these prohibitive activities support the point furthermore.

Harris (1997) points out that, front- runners are on the lookout for “large traders” who strongly want to complete a trade. Then they make short-term trading profits by front-running these large traders. SEBI defines a “bulk” deal as “all transactions in a scrip (on an exchange) where total quantity of shares bought/sold is more than 0.5 per cent of the number of equity shares of the company listed on the exchange.”

The quantitative limit of 0.5 per cent could be reached through one or more transactions executed during the day in the normal market segment. In an effort to improve transparency in the Indian capital markets, SEBI mandated the disclosure of bulk deals in the year 2004.

An analysis of 80,704 trades over the past six years to see if there is any evidence of “trade-based manipulation” in the context of bulk trades on NSE and BSE, for all NSE listed stocks, by Ms Nupur Pavan Bang (ISB, Hyderabad), Mr Chakrapani Chaturvedula (IMT, Hyderabad), and Mr Nikhil Rastogi (IMT, Hyderabad), shows that there is ample evidence of front running, with significant impact of bulk trades on the share prices.

A person investing in a small-cap stock, ten days before the bulk deal and off loading it the day after the bulk deal can make 9.58 per cent in this 12-day period . Similarly, he can make 4.79 per cent in the case of large-cap stocks in 11 days .

Practical Difficulties

The results are obvious as finding liquidity for bulk deals in small-cap stocks is more difficult and may signal the presence of more information in the trade. Also, because of liquidity issues, the broker might need more time, and may contact more people to find buyers/ sellers for the small-cap stocks. This results in more information leakage and front running.

Front-running facilitated by information leakage distorts the market integrity and can create adverse selection problems that limit market participation and inhibit efficient capital allocation. Therefore, a much stronger role for Government regulation is required to discourage manipulation in emerging markets.

Behavioural pattern

They also find that while the buyer-initiated trades result in a cumulative return of approximately 4.2 per cent over a 21-day period, but the seller-initiated trades do not see an expected dip in price over the same period.

This is in tune with the proven investor behavior of reacting swiftly to good news (bulk buying indicate good news) and being reluctant to react to bad news (bulk selling indicates bad news).

While there is need for stringent norms to regulate the bulk trades, the regulator must pay special attention to bringing more transparency and liquidity in the small-cap stocks. Due to the illiquidity in the small-cap segment, the intermediaries are able to front run the bulk orders of their customers more easily.

The surveillance activities taken up by SEBI, followed by investigative actions, need to be spruced up.

In a research carried out by Allen and others, published in the year 2007, they find that the ratio between the number of investigative actions taken up by to the number of companies under its jurisdiction was 0.09 for SEBI which is dismal when compared to SEC’s (Securities Exchange Commission) 0.52. Things do not seem to have improved in the recent years.