What is the legal ruling for authorizing a bank to purchase and trade shares, such as the Amanah Fund at the Saudi British Bank?

We have no knowledge of the safety deposit box at the Saudi British Bank. If the bank deals in usury (riba), it most likely does not adhere to Sharia-compliant regulations in its transactions. Trading in shares is permissible on condition that: the company's activity is lawful, the company avoids Sharia violations such as gharar (excessive uncertainty) and maysir (gambling), and it does not invest its funds in usurious banks. There is no objection to appointing banks, companies, or individuals to buy and sell shares if the aforementioned conditions are met.