Insider trading can affect stock prices, but it's not clear how corporate governance factors into this. A study looked at how board characteristics impact insider trading and stock price efficiency. They found that boards with more independence, smaller size, and higher debt levels reduce insider profits. However, insider trading activities don't seem to be influenced by the firm's governance. Good governance can lower insider profits and make stock prices more efficient. The study used data from 250 companies in the S&P 500 Index from 2000 to 2005.