The market has spiked in the last 10 months.

Interest rates just saw a spike after Donald Trump got elected on Tuesday night.

If your income stays the same, but the market spikes and value goes up- your cap rate goes down right?  

I believe I can take that 50K and do at least 6% (hopefully more) once I find the right deal with the right amount of renovations at this point in my life--31 with 2 kids.Cons of refi with 50K cash out:-back to the puny $250/mo towards principal with the 30yrs-slightly higher interest rates since it's spiked from 3.4% to 3.88% in the past 2 weeks.

The banks realized they were losing out back in the 80's when rates spiked so they stopped writing assignment clauses in mortgages.

I found one that broke it down by decade but didnt go any deeper to see any dips or spikes.

You'll need to pay them double to spike their interest, usually they get paid 10/hr. 28 units can't afford full time maintenance.

our market is pretty steady, we never see spikes, even through the crash, we maybe lost 20% from the top of the market. that being said, its not common to sell a house quick either, so a 150 DOM is pretty standard, even if you are priced right. 

But could bad tenants also contribute to the rent spikes?

The biggest issue I think you will have is when the electric bill spikes to $500 one month.