The Options Clearing Corporation registered a huge increase in required initial margin from clearing members in the year to December 2017. Over the same period, there was a drop in the number of times the amount of margin held against members’ accounts fell short of their actual exposure.

Net initial margin demanded by the OCC from clearing members, also known as ‘house initial margin’, grew from $6.6 billion to$13.1 billion year-on-year, an increase of 98%. Over the last three months of 2017