Mainly because these stock sectors are relatively large, there are some relatively large fund types resident in them.

The amount of funds such as hot money is relatively small, so it is difficult to control the oil stain of a large-cap stock that can be docked with Shanghai Stock Connect or Shenzhen Stock Connect. Those stocks with small plates and less circulation are preferred, because such stocks are easy to open positions and sell.

Large-cap stocks are generally controlled by some large funds, and it is difficult to control such small forces as hot money.