如果今天涨或跌不多的话，based on SPX OE DAY DATA， 这个月将是历史上 top 5 monthly OE gainer (from prior OE to this OE, 假设option was available then and it's the third Friday or 3rd Thursday if 3rd Friday was not a trading day, like 2025-04)
＊这个月用的是周四收盘价。
to be complete, this was the top x loser.
