There is a common phenomenon in the fluctuation of A-share market, in which large-cap stocks and small-cap stocks take turns to prevail. In a turbulent city, the market changes rapidly. Today, large-cap stocks are rising, and tomorrow they may turn to small-cap stocks. However, the market funds are limited, and the funds rotate high and low, and different indexes also have different performances. This is commonly known as "28-wheel rotation".

The "two" in the 28th round represents 20% of large-cap stocks with large market value, and the "eight" represents 80% of small-cap stocks with small market value. 28 rounds means that large-cap stocks and small-cap stocks are constantly switched and staged in turn. By looking at the "28-round movement" function of the selected funds, we can find that since May this year, the CSI 500 index representing small and medium-sized stocks has begun to overtake the SSE 50 index representing large-cap heavyweights.