So the third Friday of March, June, September and December has this unique thing - well, not that unique, it happens four times a year - where stock options, stock index futures and stock index options all expire.

因此，三月、六月、九月和十二月的第三个星期五有一个独特的事情——好吧，不是那么独特，一年发生四次——股票期权、股指期货和股指期权都会到期。