What is the ruling on trading stocks in American companies that operate in permissible matters such as car manufacturing or electronics? I have heard from some websites that it is forbidden to deal with some of them because they have income from interest and so on. How can I know whether the stock of this company is permissible to trade and that this one is forbidden, knowing that I do not buy stocks from tobacco and alcohol companies in the first place? Should I research each company and its accounts to see if they have income from interest or not, because this is difficult for me?