Informed options trading prior to insider trades
研究发现，公司内部人股票交易前，期权市场会出现异常波动价差，表明存在知情期权交易；该现象在大型内幕交易、腐败地区企业及信息不对称高的公司中更显著，且与交易后异常回报正相关。
Abstract We find abnormal volatility spreads in the options market immediately before corporate insider stock trades, suggesting informed options trading prior to insider trades. The informed options trading is more pronounced for large insider trades, firms in more corrupt areas, and insider purchases in firms with high information asymmetry. Furthermore, the abnormal volatility spreads are positively associated with the post‐trade abnormal returns. In the aftermath of the Securities and Exchange Commission's squawk box cases, informed options trading before insider trades mostly disappeared except for a group of insider stock sales related to insider derivatives transactions such as employee stock options exercises.