The basic unit of ETF physical purchase and redemption is called "creation unit" or "physical purchase base". The "minimum purchase and redemption unit" of each ETF may be different. Take the first ETF of SSE 50 Index as an example, its "minimum purchase and redemption unit" is one million fund shares. Due to the large amount of the "minimum purchase and redemption unit", under normal circumstances, only institutional investors such as brokers and individual investors with large assets can participate in the "physical purchase and redemption" of ETF. The basic unit of ETF subscription and redemption is initially set at 6.5438+0 million, and the equivalent value changes with the current market value. Due to stock suspension and other reasons, ETF will also introduce a cash substitution model, allowing investors to make cash substitution at a ratio not higher than 5% of the total subscription value in case of stock suspension, poor liquidity of constituent stocks and adjustment of constituent stocks. The premium amount of cash substitution is calculated based on the latest price of the unit stock, which is the latest transaction price in normal trading, the daily daily limit price in the stock daily limit, the latest transaction price in the case of suspension of trading on the same day and the previous closing price in the case of suspension of trading on the same day. The scheme is initially determined, and the fund manager can determine the constituent stocks of cash substitution, and the fund manager can make a reasonable quotation for cash substitution and deal with the cash entered due to subscription in time.