"Each subscription unit of Shanghai Stock Exchange is 1000 shares"?

First of all, it is the basic unit of new share subscription. New shares refer to stocks that have just been issued and listed (that is, stocks that have not been traded in the secondary market).

To subscribe for Shanghai shares, the minimum subscription of the fund account number is 1000, and each 1000 is a basic unit; To purchase Shenzhen stocks, the minimum number of capital accounts is 500 shares, and each 500 shares is a basic unit.

Second, you just open an account to buy stocks, not new shares, but new investors. Subscription for new shares means subscription for newly issued shares (commonly known as innovation).