GapMan Study #1
.. There's not just more money involved than you think...
.. There's a lot more money involved than you think..
.. If you don't know what a GapMan is then check the BigFoot Hall of Fame..
Option Months Available for Trading
(Schedule of how Options are opened for trading each month,
helps to understand OiMatrix which is "OM" tab of OptionBT)
Open Interest In-The-Money Study #1
(Asks, "Is there a relationship between current in-the-money put and call
  open interest and the future direction of the market".)