The short answer is, anytime you can invest money at a higher return than it costs!
But that should only apply to a business you are familiar with and experienced at. If you are a real estate re-developer (nicer term than rehabber), or investor, you probably have no business in the stock market. Without Wall Street style resources, that’s just gambling.
Instead, leverage your existing properties to fund the down payment on new acquisitions... key words ”down payment”. You can leverage new purchases with a NuBANQ loan for 70% or more of the purchase price, and buy 3 times more property!
Scarcity of good deals in your area? Broaden your horizons. Florida is a big state and easy to travel, so watch for the next post on areas of Florida where properties are still in recession.