Definitions for "TRIPLE WITCHING HOUR"
The last trading hour on the third Friday of the quarters (Mar/Jun/Sep/Dec) when options and futures on stock indexes expire concurrently.
The four times a year that the S&P futures contract expires at the same time as the S&P 100 index option contract and option contracts on individual stocks.
The final hour of the stock market trading session on the third Friday of March, June, September, and December, when option contracts and futures contracts expire on market indexes used by program traders. The simultaneous expirations often set off heavy trading of options, futures and the underlying stocks. see also double witching hour.