The worst case scenario is if the Dollar, Bond, and Equities start going down together as the world repudiates the US Dollar Reserve Currency and Credit Bubble.
This is not a probable scenario.
The last time it happened was in 1933 in the trough of the Great Depression.
But we may have the opportunity to see something as once-in-a-lifetime and memorable as John Law's Banque Générale and the Mississipi Bubble.
Let's hope the Federal Reserve can reach deeper in its pockets for a better class of tricks than just front running the dollar and the bonds until they fall over.
Certainly anything is possible, but it does appear as though the US Long Bond is hitting a 'high note' of improbable valuation unless the world accepts a single currency dollar regime.
"Why is my language not clear to you? Because you are unable to hear what I say. You belong to your father, the devil, and you want to carry out your father’s desires. He was a murderer from the beginning, not holding to the truth, for there is no truth in him. When he lies, he speaks his native language, for he is a liar and the father of lies."
John 8:43-44

