Program Trading and Intraday Volatility in the Stock Index Futures Market and Spot Market: The Case of Korea

ABSTRACT

This study examines the effect of program trades on the price changes in the Korean stock index futures and spot markets employing intraday return and trading data. Program trades in the Korean stock market create an instant imbalance in market liquidity. However, their impact is very short-lived and limited in an economic sense. Moreover, there is little tendency for market returns to over-react to program trades. An increase in program trades results in higher spot market volatility but does not cause monotonically increasing futures market volatility. Overall, program trades do not destabilize the stock market in Korea despite some positive association between program trades and volatility.

KEYWORDS:

• Program trading
• stock index futures
• index arbitrage
• volatility
• market liquidity