Quadruple Witching

The term Quadruple Witching refers to the dates in which equities index options, equities index futures, equities options, and equities futures all expire on the same day.

In the US equities options contracts end on the third Friday of every month as well as at the end of every quarter.  In March, June, September and December, all of equities index options, equities options, equities index futures, and equities futures will expire on the same day.  The coinciding expiration dates cause increased volumes in the equities markets due to the fact of the heavy volume in the derivatives markets from the closing out of all of the contracts on the same day.