In this paper, we analyze the trading patterns of investors around the bubble events selected for stocks traded in Korean Stock Market from 1999 to 2013, whose holding period returns exceed 200% for 250 trading days prior to the event and then drop subsequently below -50% thereafter for the next 250 trading days. We examine whether individual investors, commonly known as noise traders, drive the bubbles, and whether institutional investors and foreign investors, known as informed traders, take an arbitrage position to shrink the pricing errors or ride the bubbles to maximize their profits. We also examine whether individual investors suffer losses due to their disposition effect even after the bubble bursts.
Major findings of this paper are as follows : First, we find that individual investors are actually shown to drive the bubbles in our full sample, whereas the burst of the bubbles are largely driven by institutional investors and foreign investors. In particular, it is shown for large-cap stocks that foreign investors take the lead in raising the price at an early stage of the bubbles and then institutional investors follow them until the bubble peak point. Second, for mid-cap and large-cap stocks, institutional investors are found to ride the bubbles from about 75 days prior to the bubble peak point, when foreign investors reverse their trades and start selling to realize profits. Such bubble riding behavior of institutional investors is consistent with the synchronization risk model of Abreu and Brunnermeier (2002, 2003), where it is optimal for informed traders to ride the bubbles until all of informed traders start selling at the bubble peak point. Third, individual investors are found to suffer losses as they keep buying the bubble stocks even after the bubble bursts due to their disposition effect.
The Unexpected Volatility of Foreigners’ Trading Behavior Effects on the Korean Stock Market Volatility
