I'm assuming you mention interest-free for religious reasons. If that's the case, there are mutual funds designed to comply specifically with various religious

I'm assuming you mention interest-free for religious reasons. If that's the case, there are mutual funds designed to comply specifically with various religious requirements (meaning the only invest in appropriate companies and revenue streams, etc) that you may want to look into. I don't know any names off the top of my head, but sometimes they go by "virtue funds."