@Scott Sambrook conventional (Fannie/Freddie) underwriting standards only require 6 months' seasoning before a new appraisal can be used to determine the value of a property for refinance purposes, but in my experience most lenders still want to see 12 months of ownership before they'll play along with that.

Turns can be costly and students like to do the under the radar subleases so there are things you need to be aware of and prepared for but overall its a great long term play.

What type of mortgage or loan should I use if I want to purchase a large amount of investment properties (about 40) at once?

Let's play a little "which market is the best" game!

Let's play a little "which market is the best" game!

Here the more bedrooms the better so if you can fit 3 that’s great but the city or county you’re in may limit you to 2 depending on size allowed plus if you’re on city water and sewer vs septic that may play a factor as well because they may require a separate septic system which is $$$.

For these reasons, I’ve spent a lot of time the past couple of months looking into the FL marketplace.I don’t know much about NH either but I agree that Western Mass and parts of Rhode Island and CT have deals that cash flow.

Play with the numbers, and see if the deals make sense.Without much experience on ARV and repairs, it will benefit you to shore up those skills ASAP so you can get more accurate offers to sellers. 

if that's the case, having an extra 20% in the deal from either buying low or adding value will be a big help in weathering the storm. this will make it that even if you ahve to sell, you could still earn some money or break even. additionally, with a multi it's generally more of a cash flow play, and if that's the case an economic dip won't be too big of a deal if you are cash flowing an acceptable amount with a buffer included. lastly if you get into a deal and have extra equity, you could bring in another investor in the future and "sell" the extra equity to them, while still staying in the deal. there are other options, like subject too's and rent to owns that may work here but for me buy low is the best defense. 

Some real estate investment plays are for appreciation and I don’t have data or a graph to present but my educated guess is that it is in the minority as much of it is for cash flow and or value added propositions to force the appreciation.