My recommendation would be to choose potential markets - in several price points - that have strong rental demand and year-over-year rent increases and that also are in markets that are appreciating. 

You would really want to do your own due diligence and probably fly to the market(s) you'd like to invest in.

I was thinking of starting a rent increase for my 1 bedroom tenant voucher due it being low and well under fair market value(Based on  hud and zip code) but my tenant is in the process of having a caretaker for her disability and getting approved for a two bedroom voucher.

How would you research a potential market?

Much like other markets in the Midwest, investors go to our market because of the low barrier to entry.

What is the market rent?

I am considering getting into this space (looking at some courses), but worried that its too late, and that deep local market knowledge/understanding of buyers/connection with developers etc is required to make this work, which only incumbent/long term investors will have and would be hard for a new entrant starting from scratch to catch-up...is my hypothesis valid in your opinion ?

We own SFHs in Columbia SC and like that market.

@Danielle Levy a lot of questions regarding your accusations:1) What are the average Days On Market (DOM) for rentals in this "hot" market?

The capital required for Denver, and limited cash flow makes it a tough market to get your next one.