Bunds are the new treasuries, when they want to be
 
            Posted by 
Izabella Kaminska on Aug 20 16:07.                              FT Alphaville 
wondered earlier why German bunds would be affected by convexity hedging dynamics in the US, one of the factors that is supposedly driving 10-year US bond yields to fresh lows.
Could it all be down to that old devil, 
correlation?
The following chart shows the potential arbitrage opportunity from synthetically replicating a US treasury by buying a bund instead.
The process involves (bear with us) paying for a bund, then a fixed rate to swap to a floating euro, then a basis swap to a floating USD to receive a fixed rate in dollars.
The below compares the difference between that return and a US Treasury yield:

(H/T Sean Corrigan at Diapason Commodities for the chart.)
As can be seen everywhere except in the 30-year option — where the trade has underperformed the US Treasury most of the time since November 2008 — the arbitrage opportunity has been almost completely closed in.
Of course, it’s worth pointing out that the US 30-year Treasury swap has been 
negative since exactly November 2008 too.
Furthermore, you’ll notice that the 10-year option (yellow line) dipped below zero most prominently in 
March/April and then again 
July/August — which happens to be the exact time the US 10-year Treasury swap went negative too.
So does that explain the mystery of the negative US swap rate?

We’ll be interested to hear your views.
 
Related links:
Unravelling the mystery of the negative US swap rate – FT Alphaville
Swooning canaries, exploding debt - FT Alphaville
The negative swap time-warp- FT Alphaville