I know that Dow Jones, MSCI, Russell, and S&P have many halal or Islamic indices in different markets across the world (e.g. Dow Jones Islamic Market Titans 100, MSCI ACWI, etc). Can we assume any company listed on any of these Islamic indices is okay to invest in? Or do we need to check the Shariah board for each market to see who has approved it (I have noticed these companies have indices in many smaller markets as well like India, Turkey, Canada, etc)
Also, do you know of any other halal indices not listed here?