Reading a book on investing at the moment and talks about real estate and shares etc.
It indicates that when you buy real estate you protect yourself with insurance should things go wrong in the investment, be it Building insurance and Landlord insurance etc.
Then it goes on to say to protect yourself when you have shares in stocks incase the market goes down. It doesn't go into specifics but mentions using options.
Asking if one of the learnered forumites could expalin how you do this.