Ding crab effect (also known as autumn official effect) is a unique phenomenon in Hong Kong stock market. /KOOC-0/992/KOOC-0/0/KOOC-0/0 In October, Hong Kong TVB broadcasted the TV series "Big Times" starring Adam Cheng. The story tells that Ding Xie, played by Adam Cheng, often made huge profits by shorting Hang Seng Index futures when the stock market was in a bear market. At that time, the Hong Kong stock market plummeted and investors suffered heavy losses. So the term "Ding Crab Effect" came into being. Because Adam Cheng is nicknamed "Qiu Guan", it is also called "Autumn Official Effect". More than a decade later, almost every time a TV series starring Adam Cheng is broadcast, the stock market will drop sharply.

According to the statistics of the Ding Crab Effect of Hang Seng Index, the duration is generally more than one month (5 -8 weeks).