So, what vortex in the universe make Real Estate not just immune but reverse power to this? 

I am no way predicting a replay of those events but it did happen.. and for those to think that rentals are immune well they just don't know what they don't know.. in some markets sure but in many NOPE> 

The are getting harder to treat as they are becoming immune to some of the chemicals previously used.

:D Using bleach to get rid of mold is a lot more dangerous to those using it than remediation methods that actually remove the mold (not just kill it).Here is what the EPA says:"The purpose of mold remediation is to remove the mold to prevent human exposure and damage to building materials and furnishings....The use of a biocide, such as chlorine bleach, is not recommended as a routine practice during mold remediation, although there may be instances where professional judgment may indicate its use (for example, when immune-compromised individuals are present)."

Are these immune from regulation? 

When things go south during times like these i dont see any type of rental in okc that is really immune based on my past experience.  

@Gil Segev I’m not saying a recession doesn’t impact everyone- no one is completely immune to economic downturns.

Owen, although I agree for the most part of your analogy, I disagree with the notion that cash flow is somewhat immune trends and fluctuation.

Mostly it hits infants, or those with compromised immune systems, like the elderly.

@Tim FitzGerald   good points the only rebuttal I have to your post is RE agents contractors appraisers lenders etc are all licensed and they stand to lose their livelihood is they screw up badly enough.. a non licensed wholesaler can botch a deal and they are immune .. no other industry would allow someone with no training no licensing to control thousands of dollars worth of assets they do not own. and if it goes bad just say well I am sorry it did not work..