A Comparison of Price Efficiency between Korean New Market and Main Board Open Access

In this paper, we make a comparison of price efficiency between the new market (KOSDAQ) and the main board (KOSPI) in the Korean stock market. More specifically, we evaluate the relative price efficiency of both markets by comparing the speed, degree and accuracy in process of intraday price discovery. Each market’s speed and degree of price discovery are measured by WPC (weighted price contribution) devised by Barclay and Warner (1993) and WPCT (weighted price contribution per trade) proposed by Barclay and Hendershott (2003), respectively. Each market’s accuracy of price discovery is measured by unbiased regression coefficient used by Biais et al. (1999). We analyze 535 KOSPI stocks and 803 KOSDAQ stocks using 1-minute-interval transaction data collected from Bloomberg. The major findings of this paper are summarized as follows: Fist, the price discovery in KOSDAQ, the new market is slower than in KOSPI, the main board. Second, the morning session’s degree of price discovery per trade in KOSDAQ is smaller than KOSPI. Finally, the price discovery in KOSDAQ is more accurate than in KOSPI. Overall, our results indicate that the prices of KOSDAQ stocks are as efficient as the prices of KOSPI stocks, thought they have smaller firm size, younger ages, and greater uncertainty in cash flow and asset value than the main board stocks do.