How to protect your investments against a market crash

[Damara Montaque]

I was reading in one of Brandon Turners books about how he will only purchase a property for 20% less than what it’s worth in order to protect against a market crash.

My question is, will the market not drop less than 20% so you don’t go underwater with a property? What if it does drop more than 20%? Are there any strategies to protect against this?

Thank you for your help!