14 February 2014

Statistical possibility of manipulation in the Indian securities markets.

My friends and colleagues at IIM,A have written a very interesting paper titled "High Frequency Manipulation at Futures Expiry: The Case of Cash Settled Indian Single Stock Futures", where they use a statistical/econometric tool to estimate the possibility of manipulation in the stock markets. The paper by Prof. Sobhesh Agarwalla, Prof. Joshy Jacob and Prof. JR Varma described in their own words is about:

Futures markets are known to be vulnerable to manipulation, and despite the presence of a variety of mechanisms to prevent such manipulation, instances of market manipulation have been found in some of the largest and most liquid futures markets worldwide. In 2013, the Securities and Exchange Board of India identified a case of alleged manipulation (in September 2012) of the settlement price of cash settled single stock futures based on high frequency circular trading. As is well known, it is easy for any well-endowed manipulator to manipulate the price; the real challenge for the manipulator is to make the manipulation profitable. The use of high frequency circular trading of the form alleged in the SEBI order makes many forms of manipulation profitable, and makes futures market manipulation a much bigger problem than previously thought. 

As argued by Pirrong (2004), it is more practical to detect and punish manipulation than to try and prevent it. We develop an econometric technique that uses high frequency data and which can be integrated with the automated surveillance system to identify suspected cases of high frequency manipulation at futures expiry. We then use these techniques to identify a few suspected cases of manipulation. Needless to say, human judgement needs to be applied to decide which, if any, of these cases need to be taken up for investigation (and, after that, possible prosecution). This judgement is beyond the scope of our paper, and we refrain from making any judgement on whether any of the identified cases constitutes actual market manipulation.

The paper can be downloaded from SSRN website.

Those who recall the US paper several years back by Prof. Erik Lie  which resulted in options backdating enforcement action or another paper further back in the 1990s by Prof. Christie and Schultz titled "Why do Nasdaq market makers avoid odd-eighth quotes"  on the Nasdaq's oddly priced trades which also resulted in extensive enforcement action against the exchange and the market makers would find this of substantial interest. This should of course be of interest to SEBI to dig deeper to uncover evidence of manipulation.

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