Theory and Evidence of Arbitrage Trading of Equity Futures

The equity futures market was opened in May 6th, 2008 for the first time in Korea but nonetheless it has rarely been researched since. In this paper, we examine whether the market, combined with the stock market, its underlying market, has been offering any arbitrage opportunities to market participants for the period of May 6th, 2008 to March 11, 2010, focusing on the two futures contracts of Samsung Electronics and Hyundai Motors, the two most actively traded ones. Our findings are as follows. First, there have been arbitrage opportunities for the two futures in either direction. Second, the average time period for an arbitrage opportunity was two seconds so arbitrage transactions were feasible indeed. Third, nevertheless, some arbitrage transactions ended up with a loss because the estimated spot price at maturity to carry out an arbitrage trading turned out to be significantly different from the realized one. The discrepancy in these two prices causes a seemingly very safe arbitrage trading a risky one. This risky feature of an arbitrage trading has never been addressed in depth in a paper or a book before, and is a major contribution of this paper.