An Empirical Study on the Short-run Performance before and after the Unlock of Private Placement Stocks in the A-share Market

Private placement is an important financing tool for listed companies in China, and the lock-up arrangement is its supporting system. The Efficient Market Hypothesis suggests that, if investor expectations are unbiased, there will be no abnormal fluctuations in the stock prices of listed companies before and after the unlocking day. However, around the time of the unlocking of private placement shares, the stock prices generally show a V-shaped pattern.

Through the empirical analysis of the Chinese A-share stocks from May 8th,2006 to December 31st, 2016, I found that from the 40th day before the unlocking day to the 90th day after, the stock price showed an evident first-downward-then upward trend. The lowest price appeared near the unlocking day. Meanwhile, the greater stocks fall before the unlocking day, the greater prices rise after that. The characteristics of the distinctive difference between the stock prices before and after the unlocking day can provide investment opportunities.

By reviewing research on investor behavior, this paper suggests that the V-shaped pattern can be explained by the influence of investors’ psychological factors on their trading behavior. The general performance of the stocks before the unlocking day is negative due to the increasing uncertainty perceived by investors. After the unlocking day, the uncertainty gradually disappears and the stock rebounds. In addition, I found that stock returns during the lock-up period, shareholder background, and the length of lock-up period also had significant impacts on the V-shaped price trend.