ETF is an exchange-traded fund and an investment tool accepted by investors. A substantial increase in ETF positions generally means that ETF fund managers think that a certain industry or field in the market has a good future development momentum, so they increase the stock positions of related industries in ETF funds. For example, in recent years, ETF funds in the technology industry are active, and managers will actively invest in the stocks of technology companies in order to obtain greater returns.

Although the trading volume of ETF funds is relatively large compared with small and medium-sized stocks, investors still face risks after the ETF has increased its positions significantly. Fund managers will also actively consider security measures to reduce investment risks. For example, ETF fund managers will analyze industry trends and choose high-quality enterprises to invest. At the same time, managers will spread risks through cross-shareholding to ensure the healthy development of ETF funds.

The substantial increase in ETF positions may raise the stock prices of some industries or fields, and also affect the mood of the whole market. Because when ETF fund managers significantly increase their positions in an industry, it will bring confidence to investors and guide more investors to pay attention to related stocks. Therefore, the substantial increase of ETF positions will also affect investors' views on the industry or field through market reaction, thus affecting its future development.