The strength of the secondary note buying market fluctuates like any other.

The market is pretty well insulated from fluctuation based on the economic drivers.

Property prices didn't fluctuate even remotely close to what you hear about in the big markets. 

I live right outside of Baltimore but haven't personally been as my work hours fluctuate.

Then there are short term fluctuations.

This generally means I'll end with well over 25% equity which drives higher than "normal" cash flow... which for me, can ebb and flow with market fluctuations. 

Lake Worth seems to be filled with small multi-families but I've heard it's hard to find/ keep good tenants due to the LW utility system which supposedly has unpredictable service outages and fluctuating costs. 

Odds are that a few weeks of random market fluctuations upwards to rate will be waaay less than a bunch of rate lock extension fees multiplied by 7 loan amounts.

I also plan on looking at how the markets I am looking at fluctuated in last real estate bubble, to find a market that is less prone to wide swings in price.  

How does that work when rates are variable and payments can fluctuate?