I see very little fluctuation over the past several years. 

We can only guess where the market will be this time next year, but if I acquire roughly the same amount of property each year, the ups and downs will smooth out, the great deals in a down market will help carry the less spectacular deals in an up market and if i'm cash flowing on all properties at purchase I shouldn't have too many issues since rents don't fluctuate nearly as much as home values.This is the one area where I get a little "paralysis by analysis" wondering if we are in an up or down market today (my newbie opinion is we are somewhere in the middle).  

However, since the NNN leases are usually very long term (20 yrs) and sometimes without rent increases, they are very sensitive to interest fluctuations.  

There is no risk once your diversified investments are a sufficient safety net.Leaving surplus cash as equity in properties is high risk due to market fluctuations.

The amount of sleep I need tends to fluctuate between 6 to 8 or even 9 hours of sleep.

We have around 1000 units under management that fluctuates up and down based on property sales or new management right now.

In that sense it's the most fixed piece of the income on a property since it doesn't fluctuate or require assumptions.I also think of Realestate as more like "bonds" in a traditional stock portfolio- a form of diversification  of an over all investment portfolio that includes stocks, Realestate and cash (personally I'm not interested in bonds at this point in my life).Thoughts welcome.

Done correctly there should be minimal fluctuations through the year.

I'm hoping that the new fracking techniques make the area more competitive, resulting in less fluctuations in the job market, but we'll see. 

Cheap housing without a lot of fluctuation in market pricing and a large military installation.