I am in multiple markets and see this as a societal trend.

There will be multiple issues unfolding at the same time as there are always something going on!

January rolled around and we suddenly had multiple offers.

Hi Shayan--Totally agree with Chris Seveney...I use multiple metrics for a deal. 

While concerns about vacancies are valid, a great deal will often outweigh the short-term impact of a couple of months without rent, especially considering that it usually takes time to close on a property.

I've done multiple BRRRRs myself and tend to find the best opportunities in C, C+, and B- neighborhoods where the inventory of distressed homes is still there. 

i would do fha and then go conventional to buy multiple properties.

Tax impacts include deferred gains, adjusted cost basis affecting future depreciation, and strict adherence to IRS timelines.

Impacted Areas. 

If there's a hole, it may be a red flag.b) sensitivity analysis: I examine all the assumptions, and make sure I can live with the worst case scenarios.c) "Stall and see": if they are getting money over multiple years, and there is no penalty for investing later, I would usually wait so I get some real performance data, versus having to look at theoretical pro forma information.d) Recession stress test: I will not invest in anything, until I subject it to recession level stress and see if I can live with the result.