Directors, board members, and large shareholders are just some of those who might have non-public material information about their firm. Even though this information could be easily used to profit by trading their own stocks, this insider trading behavior is strictly prohibited. But how profitable can it be? We can study insider trading in the time when it wasn’t regulated at all – in the early 1700s. The 300 hundred-year-old dataset consists of data recovered from original handwritten ledger books and transfer files of the three largest companies in the London stock market at the time. It gives us a glimpse into the evidence of how big the insider’s advantage is, and the result is quite surprising – the authors calculated their outperformance to just 7% per year.