I think your numbers are a little high (but still very good) as you'll need to consider your carry costs during the 4 months.

If so, you can carry back the NOL for at least two years and use it to offset taxable income in those years.

double check your outlay of costs on arbitrage. you may not be paying to buy a property, but you will have to furnish it, carry insurance, and pay the owner their money too. and at the end of the day, the owner can stop your "business" and take it off the market or sell it at any time. 

Yet, you should never say never and any investment carries a certain degree of risk.

What is your view of "passive" income and are you okay with the higher risk it carries?

Even then, if you've built up enough carry-forward losses, a nice capital gain may not trigger any taxes to be paid. 

Cash to invest (enough for deposits, skin in the game lenders want you to have, closing costs, carrying costs, and to kick off rehab work).2.) 

A HELOC can be flexible, but ensure you have solid cash flow to cover repayments. 401K loans carry risks like penalties if not repaid on time.5.

Which profits can than be utilized to carry forward into the then "good" MFH acquisition timing of things. 

@Mike Dymski, in my experience raising institutional capital early in my career, I would disagree about "following a sponsor" for years, and actually many of the deal level analytics (a majority of institutional investors invest in funds not deals), but your point is generally correct.Ultimately, what I see a lot on these forums is that a lot of people are relying on the investment manager to also educate them on macro economic conditions, which will always carry a natural bias towards their types of offerings.