What is the ruling on purchasing shares of companies operating in pharmaceuticals, car insurance, and tourist hotels from a government bank that deals with interest, knowing that these are the only banks available for selling shares, and that the bank declares its intention to offer Sharia-compliant deals and transition to operating under its regulations in the future?

For the trading of shares to be valid, they must be pure—neither prohibited nor mixed.

If the shares are pure, it is permissible to purchase them through a bank under the following conditions: 1. The bank buys the shares for itself, and they enter its portfolio. 2. The bank sells them to the customer for a spot or deferred price. 3. The customer may sell them on the stock exchange or hold them after they have entered his portfolio. However, it is not permissible to sell them back to the same bank from which they were purchased. 4. The bank is not permitted to stipulate a penalty for late payment when the customer purchases the shares at a deferred price.

However, if the bank's role is to pay the price of the shares on behalf of the customer and then recover it with an increase, this constitutes a prohibited usurious loan.