Stock liquidity, firm size and return persistence around mergers and acquisitions announcement

Abstract

The paper examines market liquidity and size of 396 US firms engaged in mergers and acquisitions (M&A). The announcement-period returns are estimated using Carhart’s four-factor model and estimated using two regression specifications. The results suggest that the return continuation depends on the degree of liquidity and the firm size. The positive and significant cumulative abnormal returns (CARs) under both the specifications with exception to the acquiring firms are found. Under the generalized autoregressive conditional heteroskedasticity (GARCH) model due to Glosten et al. (1993), hereafter, GJR-GARCH, the pre-event CARs are significant and persistent in contrast to the estimation based on the ordinary least squares (OLS) regression. This suggests possible leakage of information prior to an event announcement and further lends support to the contract theory of information asymmetry and signalling. It is also found that the target firms exhibit positive and significant post-event CARs for the mid-cap stocks. Whereas, for the acquirer firms, the post-event CARs for the small trading volume stocks are positive and significant. The results are robust to bootstrapping simulations.

Keywords

• announcement-period returns
• event study
• firm size
• liquidity
• mergers and acquisitions