Ruling on short-term mudaarabah (buying and selling) in mixed and haraam shares
Question

                What is the ruling on short-term mudaarabah (buying and selling) in mixed and haraam companies in the stock market?.
Praise be to Allah.Firstly: 
It is not 
    permissible to buy shares in companies that deal in haraam things, such as 
    riba etc, whether the haraam is small or great, because a share is part of 
    the company’s wealth, and its dealing in haraam means that everyone who 
    invests in it is a partner in that haraam. 
Secondly: 
It is not 
    permissible to trade in mixed and haraam shares, by buying, selling or 
    investing, whether that is short term or long term, because it is not 
    permissible to sell haraam things, whether in small or large amounts. A 
    contract that involves that is a contract which it is not permitted to enter 
    into.
 Dr. 
    Muhammad ibn Su’ood al-‘Usaymi (may Allaah preserve him) said: Some people 
    differentiate between mudaarabah (buying and selling) and long-term 
    investment and say that the one who engages in mudaarabah does not have to 
    worry if he buys a share in a company that gives or takes riba-based loans. 
    My response is to ask these people: What shar’i justification do you have 
    for the profit that you make on the shares when they go up? He will never 
    have any answer but to say: I am a partner in that company. 
Similarly I 
    say to him: what if the company were to make a loss a few minutes after you 
    bought shares? Can you deny your connection to the company so that you will 
    not have to bear any loss? Of course he will not be able to do that, and he 
    will bear the same losses as all other regular shareholders. Not only that, 
    if the company were to merge with another company or it were to be sold to 
    another company, or it went bankrupt or was no longer on the stock market or 
    its licence was taken away, all of that would have an effect on the mudaarib 
    (one who buys and sells within a short period of time) and investor alike. 
    So there is no difference between the mudaarib and the investor. End quote. 
He was also 
    asked about the ruling on mudaarabah (buying and selling) in mixed shares? 
He replied: 
It is not 
    permissible according to the majority of scholars, except in the case of 
    “pure” shares, whether it is mudaarabah or investment. End quote. 
And Allaah 
    knows best.