Announcement disclosure. At present, Shanghai Stock Exchange and Shenzhen Stock Exchange have different information disclosure requirements for ETFs in their respective markets. Among them, the Shanghai Stock Exchange announced the changes of ETF shares on a weekly basis, and the Shenzhen Stock Exchange disclosed them on a daily basis. But the actual operation is not so standardized, and the above delay information is free. However, if there is a huge net purchase or net redemption caused by an accident, the fund company will start an emergency plan and report it to the competent department. Banks will convey this valuable news to relevant stakeholders in various ways, but when ordinary customers know it, they have missed the arbitrage opportunity.
Since the Shanghai and Shenzhen Stock Exchanges regularly announce the share and changes of each ETF, when the ETF share rises, it means that more funds will be allocated to the index constituent stocks, thus driving the stock index to rise; When the ETF share drops, it means that the funds are withdrawn from the constituent stocks, and the stock index will also fall. The logical relationship implied in this view is that the increase or decrease of ETF subscription leads to the change of stock index. But the same event can also be understood from another angle: when the stock index rises for other reasons, many investors follow suit to avoid stepping on the market, and the entry of new funds further pushes up the stock index, forming a positive feedback cycle. From this relationship, it seems that the rise of stock index is the main reason for the increase of ETF subscription.