There are many international brokers that provide services to non-US residents, like Interactive Brokers, TD Ameritrade, etc. However I wonder if they are letting their customers to buy actual stocks, or rather some kind of derivatives that simply follow prices of those stocks?
Let's say I opened an account with Interactive Brokers, and bought some shares of Tesla. Do I now actually own Tesla stocks or the whole ownership is local to Interactive Brokers? For example if Interactive Brokers suddenly disappears (goes bankrupt or wiped off the face of Earth for any other reason) will my shares disappear with it?
What I'm looking for is a way to retrieve my shares and keep them independent of any particular broker, so that I could for example buy them with one broker and sell with another.