Here is how it might play out...if someone has 10k stocks at $27....Assuming worst case 4.0 / year dividend., in 1 year it will get 40k dividend .So its fine even if stock drops to $22. But most likely stock will be back to 30 dollar. I don't see much risk at this.
The worst case scenario is the Fed raises the funds rates so rapidly that AGNC starts to have negative earnings. The next question is whether they can return to positive earnings before they run out of cash. If not then they become insolvent. That is the only risk that matters because you can't ride this one out because it is a complete loss.