Whenever you trade an option, someone takes the other side of your trade. Have you ever wondered who that person is? Professional market makers, whose job is to provide a market in the options on that stock, often do. But who else trades options and how can you use this information?

A recent academic study of option market activity analyzed 12 years of trading data for options listed at the Chicago Board Options Exchange (CBOE) to see who trades options and why they do it.