Key audit matters and insider trading profitability: Evidence from China

The debate as to whether or not an expanded audit report is informative to the market persists, either from experimental and empirical study perspectives. With the utilization of 4,336 firm-year Chinese observations from 2016 to 2017, this study investigates whether the mandatory disclosure of key audit matters (KAMs) restricts insider trading profitability in China. The main test and robustness tests confirm the significant and negative relationship between KAM disclosure and insider trading profitability in the Chinese capital market. The study further explores the impact of KAMs’ textual characteristics using the KAM data from 2017 to 2020. The results suggest that firm-specific KAMs, longer KAMs, more readable KAMs, and more accurate KAMs reduce the insider trading profitability. Supplementary analysis shows that this effect only exists for opportunistic insider trading. In addition, the effect of KAM disclosure on insider trading profitability is further amplified by high institutional ownership, auditor industry specialization, and KAM with goodwill impairment matter. Overall, the study presents some evidence of the communicative value of KAM disclosure and provides a practical means to restrict insiders’ opportunistic behavior, highlighting the decision-making usefulness of KAMs for external investors.