You’ll never have a “Christian portfolio”. We don’t live in a Christian world. We live in a fallen world where “heaven is our home”. It’s why the Bible says we aren’t citizens here.
It’s why the Bible calls us sojourners here: https://www.biblegateway.com/resources/encyclopedia-of-the-bible/Sojourner
Additionally, when a company gives money to a charity, it’s out of their earnings (from people buying their products or services, but not from buying their company’s shares).
But many people have Microsoft products, Google or Apple products, Facebook, Amazon, etc. None of those are Christian companies and they certainly don’t give to Christian causes. Our car companies here give to very immoral causes as well.