The Information Content of Insider Call Options Trading
研究内部人买入和卖出看涨期权交易的信息含量，发现单独买入看涨期权对股价只有短期影响，而伴随股票买入的看涨期权买入有长期正面影响；伴随股票卖出的看涨期权买入则传递负面信号，卖出看涨期权后股价下跌，表明这些交易由负面信息驱动。
We examine the information content of two forms of insider trading, insider buy-, and sell-call transactions. We find that the information carried by stand-alone call purchases has only a short term impact on stock prices, but over a longer term, call purchases accompanied by stock purchases have a positive impact. Call purchases accompanied by stock sales signal negative information about the firm, suggesting that some insiders use complicated trading strategies to manipulate the market. Insider sell-call transactions are followed by negative returns, indicating these transactions are driven by negative information about the firm.