In real estate, your passive opportunities are in private lending and rental properties. Private lending commonly involves lending funds to a real estate investor or business in exchange for a set return and length of time. (Full disclosure: I am co-partner of a turnkey investment company.) Turnkey rental properties allow the investor to be as hands-off as they like. This means a turnkey company purchases, rehabs, tenants and manages the property. To truly make this a passive investment, turnkey companies do all the work for you.
If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.