When buying shares in any company, we should make sure that its activities, sources and products are permissible. In other words it is not permissible to buy shares in a company whose activities are not permissible by Shariah such as interest, gambling, prostitution and the like. It is also not permissible to buy shares in a company whose activities are permissible but it lends or borrows money on the basis of Riba, because shares are part of  the company’s wealth, and the shareholder is a partner in all the transactions that go on. Every Muslim who is keen to avoid Riba and its consequences should make his/her position clear to the company, and state that he will leave if the company takes a Riba- based loan.