Friday December 17 Witch Day :) Friday, December 17, in the sense of the "Four Witch Days", which will usher in the largest option expiration date in American history! (The Fourth Witch Day refers to the third Friday of the U.S. stock market in March, June, September, and December each year, which is the expiry settlement date of derivative financial products.) According to the statistics of the big data of the U.S. stock market, the total value is 4.3 trillion yuan. US dollar stock options are about to expire, including US$2.3 trillion S&P 500 index quarterly options, US$360 billion S&P 500 E-mini futures options, US$255 billion SPY options and US$670 billion single stock options .