18-17=1If you have 18 properties, and you spinoff 17 of them with no positive impact on your balance sheet, your value is going to go down. At least initially. Regardless of the work that's been/being executed on that one property, or the intrinsic value of the potential inground.
The price drop, immediately following the spinoff, should not be of any surprise whatsoever. Nor should the relatively worthless value they'll surely apply to F4.