We've already seen how insider buyings can impact the stock price or can allow us to earn some money. Here is the insider selling, a huge portion of disposal to be honest:John Simard, a major owner of XBiotech Inc. and a director of the company, recently disposed of 500,000 shares of the company. The disposals took place at $10.00 per share, on March 17, 2016. Simard still owns 6,153,267 shares of the company. So to be honest, I think that Biotech major owner raised $5M from this disposal not for personal needs. I think this is a rational step of a major owner. You can think that 500,000 shares disposal is just 8% from the overall stake. Perhaps you are right. Yes, Xilonix just got an approval from European Medicines Agency for Xilonix. Such companies as this one always reminds me a pig in a poke. They are working in a specific field - "developing True Human™ monoclonal antibodies for treating a variety of different diseases". They don't have any revenue yet, but they raised more than $70M during the IPO. They are burning around $10M per quarter and moreover they expect a significant increase in operating expenses. Sounds really strange for me. According to their website they are too far away from FDA final approval so it can take lots of time to start monetizing their products and developments. And their stock is 10% up today!