"I would say that the gentleman writing the excellent email about a bond bubble is right on target about being cautious of declaring a bond bubble.

"Here is a comment that appeared in Comment of the Day on January 14, 2009.

" My conclusion is that those who are lending to governments at record or at least near-record low yields, are walking into a trap. The government bond bubble has yet to burst, judging from the charts, but it will burst. With bubbles, it seldom pays to delay one's exit until the downtrend is evident to all. "

David Fuller's view I've made worse calls.

Obviously, the post 2008 economic slump and QE from leading central banks has extended the bull trend in bonds, arguably making the bubble even bigger.

An analytical / behavioural point about bubbles is that people who point them out as they develop, look like fools until they burst. Similarly, the people who ride bubbles all the way to the top look like geniuses until they burst.

Lastly, what do you think will happen to the US bond market, should the US economy surprise the crowd with the vigour of its recovery several years down the road from now, rather than follow Japan's journey since 1990?

Meanwhile, the obvious point is that the bond bubble has yet to burst, not least because of all that QE. I hope you are not assuming that because it has yet to burst, that it will not eventually burst.