Prof. Jayanth R. Varma’s Financial Markets Blog

A blog on financial markets and their regulation

Potential self-trades are worse than actual self-trades

Update: While linking to Ajay Shah’s blog for a summary of global regulatory regimes on self trades, I failed to mention that the particular post that I was referring to was authored not by Ajay Shah, but by Nidhi Aggarwal, Chirag Anand, Shefali Malhotra, and Bhargavi Zaveri.

Imagine that you are bidding at an auction and after a few rounds, most bidders have dropped out and you are left bidding against one competing bidder who pushes you to a very high winning bid before giving up. Much later you find that the competing bidder who forced you to pay close to your reservation price was an accomplice of the seller. You would certainly regard that as fraudulent; and many well running auction houses have regulations preventing it. Observe that the seller did not actually sell to himself; in fact there would have been no fraud (and no profit to the seller) if he actually did so. The seller defrauded you not by an actual (disguised) self-trade but by a (disguised) potential self-trade that did not actually happen. In fact, the best of auction houses do not prohibit actual self-trades: when the auction does not achieve the seller’s (undisclosed) reserve price, they allow the item to be “bought in” (the seller effectively buys the item from himself). So the lesson from well run auction houses is that potential self-trades (which do not happen) are much more dangerous than actual self-trades.

In the financial markets, we have lost sight of this basic intuition and focused on preventing actual self-trades instead of limiting potential self-trades. India goes overboard on this by regarding all self-trades as per se abusive. Most other countries also frown on self-trades but do not penalize bona fide self-trades; they take action only against self-trades that are manipulative in nature. However, they too regard frequent self-trades as suggestive of manipulative intent (see Ajay Shah for a nice summary of these regulatory regimes). Many exchanges and commercial software around the world therefore now provide automated methods of preventing self-trades: when an incoming order by an entity would execute against a pre-existing order on the opposite side by the same entity, these automated procedures cancel either the incoming order or the resting order or both.

A little reflection on the auction example would show that the whole idea of automated self-trade prevention is an utterly misguided response to an even more misguided regulatory regime. Manipulation does not happen when the trade is executed: it happens when the order is entered into the system. The first sign that the regulators are understanding this truth is in the complaint that the US Commodity and Futures Trading Commission (CFTC) filed against Oystacher and others last month. Para 53 of the complaint states:

Oystacher.and 3 Red manually traded these futures markets, using a commercially available trading platform, which included a function called “avoid orders that cross.” The purpose of this function is to prevent a trader’s own orders from matching with one another. Defendants exploited this functionality to place orders which automatically and almost simultaneously canceled existing orders on the opposite side of the market (that would have matched with the new orders) and thereby effectuated their manipulative and deceptive spoofing scheme …

Far from preventing manipulation, automated self-trade prevention software is actually facilitating market manipulation. This might appear counter intuitive to many regulators, but is not at all surprising when one thinks through the auction example.


One response to “Potential self-trades are worse than actual self-trades

  1. Pingback: In the sister blog during October and November 2015 | Prof. Jayanth R Varma's blog on computing

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