I’m just not sure where SGEN trades if the deal doesn’t go through. It’s a tempting arb play for sure and I don’t blame you for holding onto your shares
I would guess SGEN would drop about as much the price difference between now and the PFE buyout price. That spread is $36 ($229 vs $193) so if the deal gets nixed then that would drop the SGEN price into the $150s. That would be a bit painful but I would still own a company with rapidly growing earnings.