What are the credit ways for securities companies to provide margin financing and securities lending to customers?

What are the credit ways for securities companies to provide margin financing and securities lending to customers? There are generally two credit ways for securities companies to provide margin financing and securities lending to customers: (1) fixed credit way, that is, within the credit line and contract period, the amount and period of funds (securities) used by customers are fixed. And charge interest (fees) according to the amount and time limit agreed in the contract; (2) Non-fixed method, that is, the amount and duration of funds (securities) used by customers are within the credit line and the contract term, and customers can use and repay them according to the needs, and charge interest (fees) according to the actual amount and duration.