Kind of like what happened with the housing bubble?
Just kidding since you are a realtor.
Most investors, who are buying rental properties, are not buying expensive properties. There has to be a margin of profit, and if the property has a mortgage, the profit margin is greatly narrowed.
While affected by the housing bubble somewhat....it has been minimal, simply because the lower end properties have not lost as much money and the rent amount has not decreased...so it's still an income producing property.
I have worked with investors for years....it's a much different market than primary residence purchasing. In many ways...it's much harder. Harder to find the investors specific profit margin. On the other hand...there's little to no emotion in the purchase.