Consequently, it can be deduced that there are often hidden signals embedded in the volumes seen in equity derivatives flow. Sometimes this can be seen the day before, and on other occasions this is seen over a period of time leading up to an event.
There are examples where major market events were preceded by anomalous option volumes where, if you had been hunting for the signs, you could have positioned yourself to benefit from the moves that followed. Consequently, being able to screen and interpret these signals can be of paramount importance.
As call options give the holder the right but not the obligation to purchase the underlying stock at a certain price at a certain point in time, many market participants like to screen for unusual call volumes, believing that they are a leading indicator for a potential large move upwards for the stock. An easy way to do this is via MOSO S <GO>.