You can refinance with a loan that uses your personal income and debt to income / DTI ratio or a DSCR loan that will use the rental income to structure the loan. 

I was thinking about an strategy of doing Cash Out Refinicing putting that money in the stock market (distributed in ETF and some "safer" stocks) to get around a 6% anual return (estimating that low because is the "standard" average, however my current stock portafolio has a cummulative return of 66% in the last 4 years).

If you have been waiting to refinance your home to pull out cash because of a 2%/3%/4% rate you will be happy with the rates enough to act now.

Most DSCR Lenders will require the property to be rented for a refinance (or if used as an STR for example, have some STR history)  You may be able to find an option for refinancing prior to leasing, but it will make it more challenging and will likely need a "good reason" more than just speed3.

You'll be required to keep some equity in the property, and the amount depends on the lender/program.It's not TECHNICALLY a cash out refinance, it's called delayed financing. 

We are going to be converting our purchase into a halfway house/ sober living.  Anyone know of a lender that will finance a building like that? 

I was applying for a DSCR on my rental property (cash out refinance) and everything seemed ok, my FICO 680, DSCR 1.08, Appraisal $179K, LTV 65%.Unfortunately, the lender cannot close due to derogatory on record on my primary residence.

Hi, I'm looking to refinance my Canton, OH (44714) BRRR property.

From what I’ve found online, there appears to be a 6-month seasoning period before refinancing, but this may not apply to non-cashout refinances.

If you refinance you are going to lose a % of your money in refinance cost to the bank and (I assume), get a higher interest rate.