This day, called Quadruple Witching Day or ‘four witch’s day’, refers to the day when the expiration of index futures, index options, individual stock options, and individual stock futures overlap.

‘Witching Day’ appeared in the 1980s as a term referring to the day when the maturities of stock market derivatives overlap.
In the U.S., there was a ‘Triple Witching Day’ where the maturities of stock index futures, stock index options, and individual stock options overlap, and when individual stock futures began trading in December 2002, it was called Quadruple Watching Day. In Korea, as individual stock futures were introduced into the derivatives market in May 2008, it has been called’ four Witch Day’ since June.

‘Four Witch’s Day’ is the second Thursday of each quarter (3. 6. 9. December), when the maturities of 4 derivatives overlap.
This day is a day that can make a big fluctuation in the stock market and can be swung greatly on the whole, so it is called like this to mean that it is as confusing as four witches wandering around and being grumpy.

Y2021
Option Expiration
; Jan 14, Feb 10,Mar 11,Apr 8, May 13, Jun 10, July 8, Aug 12, Sep 9, Oct 10, Nov 11, Dec 9
Future Expiration
; Mar 11, Jun 10, Sep 9, Dec 9